Various quirks while overviewing the layer

[CuredPrusa]

Bug description
Randomly I can not overview the printing of a layer normally with horizontal bar from beginning to the end of the layer. Often the scroll bar goes into the other layer or begins from layer before.

There is also a problem with a vertical scroll bar - sometimes the whole model is visible (as it should be), sometimes it isn't, as if I have started to look at the layer on horizontal bar. But I didn't. It's just a bug in the software.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: 10
• Version 2.4.58.4. and 2.5.59.7
• Printer model V400