Well, I’ve just found the solution: disabling “DNS over TLS” make my boot time normal and every device reconnect correctly everytime and fast. “DNS over TLS” doesn’t work well upon reboot if I am using a static IP, but works everytime if I am using DHCP.
Strange that my most affected devices were 2 smart bulbs.
Also, if I enable “DNS over TLS” AND the side swith function (Wireguard ON/OFF) at the same time, the router doesn’t even reboot most of times and freeze with the only the power led on. Some other times it reboots very slowly but Wireguard can’t connect and there is no internet. If I move the switch it can reboot. I have this second problem using both 3.105 and 3.027, in fact I opened a topic about this some days ago: Link