Since HDMI uses digital RGB or YUV signals over three separate conductors to carry the video information, a break in one of those conductors within the HDMI cable can cause problems like you describe.

First thing is to try another HDMI cable.

If the problem is still there, do you have another laptop, or another HDMI source, to try on your display using the original cable?

Do you have another display with HDMI input that your can connect your laptop to, again using the original cable?

The picture settings menus usually only affect the individual input that you have set them to.

I'd say chances are the cable since it sounds like it gets a little more flexing from connecting/disconnecting to your laptop.

Thanks for your input. I did check the cable connection, and a pin was bent. I straightened it and everything looks good now.