Hard/Soft Line Wrap after max characters works incorrectly - with two connected monitors

Maximal characters are somehow used incorrectly. I'm using the option (in Adv.Editor) Line wrapping: hard line wrap after max characters. (or soft, it doesn't matter)
Somehow the max characters setting has to be halved to work as needed.
My Editor font is Courier New 14.
If I set max characters to 80, which is what I want, then the wrapping happens at around column 146. I also don't see the hard line on screen.
If I set max characters to 45, wrapping happens at 80, and I see the line on screen around where it should be.
But, when TeXstudio starts, if max characters is set to 45, then the lines wrap at 45, the break line shows at around 80. Then I have to change the max characters to 80, and back to 45. Then everything is where I want it.
If I start TeXstudio with max characters set to 80, then lines are wrapped at 80, the break line is beyond the end, and typing new lines will break them at ~146.

Environment

• TeXstudio: 2.12.16
• Qt: 5.12.1 R
• OS:Windows 10, 1903
• TeX distribution: MiKTeX 2.9.7000 64-bit

Expected behavior

When setting maximal characters to 80 in settings->Adv Editor, and line wrapping "soft line wrap after max. characters" or "hard line wrap after max. characters", line should wrap after 80 characters.

Actual behavior

When setting to 80, line wraps at around 146, and right indicator for end of line is at around 146.

when setting to 40, wrap is at around 75.

. When setting to 80, quitting and restarting texstudio, text wraps at 80, but end of line indicator is at 146.

when setting to 40 and restarting, wrap is at 45, but indicator at 75

How to reproduce

In Settings->Adv Editor set max characters to 80, and line wrapping "soft line wrap after max. characters". Enter in text editor a long line.

Start by reproducing the issue from Settings → Adv. Editor with soft and hard line wrapping after max characters, using two connected monitors on Windows 10. Check the editor’s wrapping and end-of-line indicator behavior both after changing the setting and after restarting TeXstudio; done means both consistently use the configured character limit.