Strange. Maybe, reset of wifi, data and bluetooth settings in your phone may help?
I disabled Management Frame Protection and now I can update apps on my phoneā¦
Strange. Does the recent updates may have change the behaviour of this so that I have to change it ?
Edit : The update was downloaded while the wifi was restarting. Changing this parameters didnāt fix the issue 
I searched on every forum on internet and eventually end up fixing this by clearing the play store cache.
In order to try to fix this, I reinstalled completely my Turris Omnia.
Adblock is not installed and everything is default.
Still not possible to use Play store.
In luci diagnostic, when trying to get gvt1.com nslookup, I have this error :
Server: 127.0.0.1
Address: 127.0.0.1#53
*** Canāt find gvt1.com: No answer
*** Canāt find gvt1.com: No answer
I tried with Google DNS forwarding or no forwardingā¦
What am I missing ? Where to look at ?
Edit: It may be normal as I am able to get redirector.gvt1.com info :
Server: 127.0.0.1
Address: 127.0.0.1#53
Name: redirector.gvt1.com
Address 1: 216.58.214.174
Address 2: 2a00:1450:4007:80e::200e
How to diagnose connectivity issue ? Is there a way to validate from the router what is expected ? All android devices connected to the Wifi canāt access the Play Store
gvt1.com is a name without any addresses on itself, so that seems expected. But I donāt know how to debug Play Store.