Dell computer monitor, weird convergence issue.

[MRX37]

I found a Dell computer monitor from about 1999, with a Toshiba CRT in it. When I first power it up, the convergence on the bottom is TERRIBLE, but then the colors slowly converge themselves, and in about 15-20 seconds, the picture is fine.

Is there a problem here, or is that how it's designed? I've never seen a monitor do this before, so I'm not sure.