Watch face keeps switching from normal to just time with blacked out background.

That happened to me once. I don't remember which one was. But it was just that watch face in particular. I tried to contact developer. No reply from him. I just deleted it.

It happens even with the default faces also. So it's not at simple as just deleting. 

I see. I've never tried default watch faces.

Perhaps you're talking about the sleep mode watch face? Settings > Sleep Mode > Watch Face

I just checked and sleep mode is off.  This is a pic of the watch face it keep defaulting to when the watch isn't touched for a few seconds. 

Some watch faces have the stealth mode, which looks like exactly this one when it's not touched for few seconds. Try to check if the one you are using has this mode and disable it. I hope it's it.

I don't believe my forerunner 255 has stealth mode. I know my instinct did. 

Correct. The 255 does not have any of the tactical features, such as stealth mode.

stealth mode is a setting in some of watch faces to save battery - so you need to do gesture to tun on all paramaters.

But you have energy save mode. Just checked - if i switch to save mode i get a same watch face.