Shelly Flood/Door not working after update to 1.11.4

Today I was careless enough to update my Shelly Floods and Shelly Door to the new firmware 1.11.4. After the update, they can't connect to my network any more. They get assiciated to the access points but it seems that they don't accept the DHCP lease (fixed) any more. I see multiple DHCP_Discover and DHCP_Offer messages, but they are not pingable and they don't connect to the cloud. The Unifi console shows them also without IP addresses. It seems that I need to manually restore the old firmware. Very disappointing.

It boiled down not not being a dhcp problem, but the problem with the dhco DNS server being ignored. I block local traffic to remote DNS servers. Added a NAT rule for all Shellys. Problem solved.