Classic Paint 1.1 Bug

For the longest time I've been using https://www.majorgeeks.com/files/details/classic_paint.html since the original was taken down in favor of the Windows 11 version, which I hate, but only until yesterday have I found a strange bug. Whenever I try to fill in a spot (specifically a 1px pencil size), a horizontal line appears. I'm wondering if anybody else is dealing with this bug and if there's any way to fix it/updated version of classic paint that I don't know about. All replies are appreciated!

Sorry, I'm new here, and I only really came to ask about this since I mainly use MSPaint for my art.

 

I forgot to provide a picture- here it is.

 

Is bumping against the rules? I mean, I hope it isn't. I don't wanna spam my own thread because there's a minor but annoying bug in my paint software.