with the upgrade to firmware 7.4.x Fint 2 I have encountered VPN disconnections after a few days, you need to disconnect and reconnect the VPN. I suddenly find all the devices OFFLine
What vpn?
What version were you on before?
Exactly where did you get the version and exactly what version?
As a note, I'll say that vpn connection may never be stable across many routers and especially when some IP address changes.
How long was it working under prior version?