I have the same problem with the port-forwarding tab. It takes about 30 sec to open and I have no rules defined. I am running Turris OS 3.9.5.
I have an even longer delay when opening the editing of FW rules (or creating new ones) from the Traffic Rules-tab. This takes about 2 minutes.
This problem existed already when I wanted to add my first own custom rule. All others were configured by the OT itself or via the FW-Zone settings. I have 6 zones connected to 3 LANs and 3 WLANs (2 of them configured for 2.4 and 5 GHz). I don’t know if this has any impact. The WLAN pages were slow when I opened them the very first time. But the rest used to be faster, even with a similar configuration.
Also editing WLAN-configurations opens very slowly (about 50 sec).
I did not check all the rest of the UI but mostly it is responding fast.
I measured both delays now twice and both measurements gave the same results.
Everything seems to work though.
I did reset the router and then reloaded the configuration. Same problem. Any suggestions