Prerequisites

• Write a descriptive title.
• Make sure you are able to repro it on the latest released version
• Search the existing issues.
• Refer to the FAQ.
• Refer to Differences between Windows PowerShell 5.1 and PowerShell.

Steps to reproduce

I have run PSCal on different PowerShell version
https://www.powershellgallery.com/packages/PSCal/1.0.3
https://github.com/digitalguy99/PSCal

I haven't installed it. I only copied this code
https://github.com/digitalguy99/PSCal/blob/main/functions_Draw-Month.ps1
https://github.com/digitalguy99/PSCal/blob/main/functions_Show-Calendar.ps1
in the command line and started than the command "Show-Calendar".

On the old Windows PowerShell 5.1 all works fine:

On PowerShell 7.3.1 there existing a problem with the background coloring:

Same with PowerShell 7.4.0 preview1 on Windows 64:

Then I have tesed it on WSL1 with OpenSUSE.
Sometimes it works right.

And sometimes it have much more problems:

Expected behavior

expected behavior: see screenshots.

Actual behavior

actual behavior: see screenshots.

Error details

wrong background on newer PowerShell versions

Environment data

see screenshots

Visuals

The screenhots are in the main part.
Because I can't post, without uploading here images, I the images again.