I had an internet outage. The router had a higher CPU load (>50%) even after rebooting. The ping to the DNS connector and gateway was greater than 1 sec. and outages.
I’m not sure if it was a provider problem, software on the router or a mis-inserted WAN cable 
The improvement in the condition occurred in temporal sequence with the WAN cable ejection and insertion - I did not do anything around the router and the temporal sequence may be a coincidence
The operator at the time was correcting a misconfiguration of my connection plan from 100/100 to 300/100.
Apr 28 19:04:17 Turris_JB netifd: Network device 'eth2' link is up
Apr 28 19:04:17 Turris_JB netifd: Network alias 'eth2' link is up
Apr 28 19:04:17 Turris_JB netifd: Interface 'wan6' has link connectivity
Apr 28 19:04:17 Turris_JB netifd: Interface 'wan6' is setting up now
Apr 28 19:04:17 Turris_JB netifd: Interface 'wan6' is now up
Apr 28 19:04:17 Turris_JB netifd: Interface 'wan' has link connectivity
Apr 28 21:04:17 Turris_JB kernel: [ 325.537123] mvneta f1034000.ethernet eth2: Link is Up - 1Gbps/Full - flow control off
Apr 28 19:04:18 Turris_JB netifd: Network device 'eth2' link is down
Apr 28 19:04:18 Turris_JB netifd: Network alias 'eth2' link is down
Apr 28 19:04:18 Turris_JB netifd: Interface 'wan6' has link connectivity loss
Apr 28 19:04:18 Turris_JB netifd: Interface 'wan6' is now down
Apr 28 19:04:18 Turris_JB netifd: Interface 'wan6' is disabled
Apr 28 19:04:18 Turris_JB netifd: Interface 'wan6' is enabled
Souhrn
Apr 28 19:04:18 Turris_JB netifd: Interface 'wan' has link connectivity loss
Apr 28 21:04:18 Turris_JB kernel: [ 326.572316] mvneta f1034000.ethernet eth2: Link is Down
Apr 28 19:04:21 Turris_JB netifd: Network device 'eth2' link is up
Apr 28 19:04:21 Turris_JB netifd: Network alias 'eth2' link is up
Apr 28 19:04:21 Turris_JB netifd: Interface 'wan6' has link connectivity
Apr 28 19:04:21 Turris_JB netifd: Interface 'wan6' is setting up now
Apr 28 19:04:21 Turris_JB netifd: Interface 'wan6' is now up
Apr 28 19:04:21 Turris_JB netifd: Interface 'wan' has link connectivity
Apr 28 21:04:21 Turris_JB kernel: [ 328.647260] mvneta f1034000.ethernet eth2: Link is Up - 1Gbps/Full - flow control off
Apr 28 19:04:22 Turris_JB firewall: Reloading firewall due to ifup of wan6 (eth2)
Apr 28 19:04:22 Turris_JB netifd: Network device 'eth2' link is down
Apr 28 19:04:22 Turris_JB netifd: Network alias 'eth2' link is down
Apr 28 19:04:22 Turris_JB netifd: Interface 'wan6' has link connectivity loss
Apr 28 19:04:22 Turris_JB netifd: Interface 'wan6' is now down
Apr 28 19:04:22 Turris_JB netifd: Interface 'wan6' is disabled
Apr 28 19:04:22 Turris_JB netifd: Interface 'wan6' is enabled
Apr 28 19:04:22 Turris_JB netifd: Interface 'wan' has link connectivity loss
Apr 28 21:04:22 Turris_JB kernel: [ 329.690247] mvneta f1034000.ethernet eth2: Link is Down
Apr 28 19:04:25 Turris_JB netifd: Network device 'eth2' link is up
Apr 28 19:04:25 Turris_JB netifd: Network alias 'eth2' link is up
Apr 28 19:04:25 Turris_JB netifd: Interface 'wan6' has link connectivity
Apr 28 19:04:25 Turris_JB netifd: Interface 'wan6' is setting up now
Apr 28 19:04:25 Turris_JB netifd: Interface 'wan6' is now up
Apr 28 19:04:25 Turris_JB netifd: Interface 'wan' has link connectivity
Apr 28 21:04:25 Turris_JB kernel: [ 332.807139] mvneta f1034000.ethernet eth2: Link is Up - 1Gbps/Full - flow control off
Apr 28 19:04:26 Turris_JB netifd: Network device 'eth2' link is down
Apr 28 19:04:26 Turris_JB netifd: Network alias 'eth2' link is down
Apr 28 19:04:26 Turris_JB netifd: Interface 'wan6' has link connectivity loss
Apr 28 19:04:26 Turris_JB netifd: Interface 'wan6' is now down
Apr 28 21:04:26 Turris_JB kernel: [ 333.850170] mvneta f1034000.ethernet eth2: Link is Down
Apr 28 19:04:26 Turris_JB netifd: Interface 'wan6' is disabled
Apr 28 19:04:26 Turris_JB netifd: Interface 'wan6' is enabled
Apr 28 19:04:26 Turris_JB netifd: Interface 'wan' has link connectivity loss
Apr 28 19:04:27 Turris_JB hostapd: wlan1: AP-STA-DISCONNECTED 7c:b5:66:6c:8c:8e
Apr 28 19:04:30 Turris_JB netifd: Network device 'eth2' link is up
Apr 28 19:04:30 Turris_JB netifd: Network alias 'eth2' link is up
Apr 28 19:04:30 Turris_JB netifd: Interface 'wan6' has link connectivity
Apr 28 19:04:30 Turris_JB netifd: Interface 'wan6' is setting up now
Apr 28 19:04:30 Turris_JB netifd: Interface 'wan6' is now up
Apr 28 19:04:30 Turris_JB netifd: Interface 'wan' has link connectivity
Apr 28 21:04:30 Turris_JB kernel: [ 338.017078] mvneta f1034000.ethernet eth2: Link is Up - 1Gbps/Full - flow control off
Apr 28 19:04:30 Turris_JB firewall: Reloading firewall due to ifup of wan6 (eth2)
Apr 28 21:04:31 Turris_JB kernel: [ 339.050156] mvneta f1034000.ethernet eth2: Link is Down
Apr 28 19:04:31 Turris_JB netifd: Network device 'eth2' link is down
Apr 28 19:04:31 Turris_JB netifd: Network alias 'eth2' link is down
Apr 28 19:04:31 Turris_JB netifd: Interface 'wan6' has link connectivity loss
Apr 28 19:04:31 Turris_JB netifd: Interface 'wan6' is now down
Apr 28 19:04:31 Turris_JB netifd: Interface 'wan6' is disabled
Apr 28 19:04:31 Turris_JB netifd: Interface 'wan6' is enabled
Apr 28 19:04:31 Turris_JB netifd: Interface 'wan' has link connectivity loss
Apr 28 19:04:34 Turris_JB netifd: Network device 'eth2' link is up
Apr 28 19:04:34 Turris_JB netifd: Network alias 'eth2' link is up
Apr 28 19:04:34 Turris_JB netifd: Interface 'wan6' has link connectivity
Apr 28 19:04:34 Turris_JB netifd: Interface 'wan6' is setting up now
Apr 28 19:04:34 Turris_JB netifd: Interface 'wan6' is now up
Apr 28 19:04:34 Turris_JB netifd: Interface 'wan' has link connectivity
Apr 28 21:04:34 Turris_JB kernel: [ 342.167225] mvneta f1034000.ethernet eth2: Link is Up - 1Gbps/Full - flow control off
Apr 28 19:04:35 Turris_JB netifd: Network device 'eth2' link is down
Apr 28 19:04:35 Turris_JB netifd: Network alias 'eth2' link is down
Apr 28 19:04:35 Turris_JB netifd: Interface 'wan6' has link connectivity loss
Apr 28 19:04:35 Turris_JB netifd: Interface 'wan6' is now down
Apr 28 19:04:35 Turris_JB netifd: Interface 'wan6' is disabled
Apr 28 19:04:35 Turris_JB netifd: Interface 'wan6' is enabled
Apr 28 19:04:35 Turris_JB netifd: Interface 'wan' has link connectivity loss
Apr 28 21:04:35 Turris_JB kernel: [ 343.211398] mvneta f1034000.ethernet eth2: Link is Down
Apr 28 19:04:37 Turris_JB netifd: Network device 'eth2' link is up
Apr 28 19:04:37 Turris_JB netifd: Network alias 'eth2' link is up
Apr 28 19:04:37 Turris_JB netifd: Interface 'wan6' has link connectivity
Apr 28 19:04:37 Turris_JB netifd: Interface 'wan6' is setting up now
Apr 28 19:04:37 Turris_JB netifd: Interface 'wan6' is now up
Apr 28 19:04:37 Turris_JB netifd: Interface 'wan' has link connectivity