Command prompt opening very small or large

While I try to access Command Prompt, it opens in full size for less than half of a second, then changes into very small size (viz. picture) near the upper left corner of a screen and after a half a second close completely.

I also noticed the command prompt appears for a split second while turning on PC, right before displaying the user login screen. (not sure if related). Not sure how long this was going on as I didn’t notice the line of a bar on top until now and I supposed it was just a flash of screen switching from displaying BIOS to windows. Did a deep antivirus search, tried to run as Administrator, updated windows, reinstalled (but kept installed apps).

Can anyone help me, point me to a solution thread or on a forum where I could get help?

Hello @BarryAllan

You can change command prompt setting by right click on bar.

As you mentioned about the command prompt appears for a split second that must be Power On Self Test (POST)screen.

Hello

please follow this link

https://answers.microsoft.com/en-us/windows/forum/all/cmd-window-very-small/33d987df-1040-49f4-8115-30f484515e2e