Connecting breaks / takes longer when updating from 4.0.6 to 4.0.8

[vanniktech]

I've narrowed it down that in my case there's something wrong when trying to update from 4.0.4. 4.0.5 & 4.0.6 still let me connect to my server right away and send messages.

However when trying to use 4.0.8 I can't seem to get a connection or at least it takes way longer than with 4.0.6. I've also tried 4.0.7 but just like others I can't install it.

What information would you need from my side in order to narrow down the cause?