The whole client freezes when there are connection issues

When my internet is gone, the whole client just freezes and everything becomes unclickable.
When I can finally open a label for example, it shows a gray background and nothing else.
This happened multiple times on both operating systems.

Shouldn’t it show the already downloaded emails?

(Originally posted by JuhG on GitHub.)

I have it at least couple of times per day.

(Originally posted by majkinetor on GitHub.)