Problems with mat-container (margins)

[ZuzkaU]

Describe the bug
Sometimes there are missing margins in the popup dialogues. It's probably some problem with mat-container. It happens only sometimes, in different browsers, I don't know yet what is the true problem.

Screenshots

[heddendorp]

This actually goes for the form fields in the toolbar as well, it would be great to figure out what makes our layouts break and reproduce it