Has anyone had trouble with speed on their tt

A very sensitive topic. Most owners don't want to know that. There are a few discussions about drifting Turntables (especially when the Sutherland timeline is used). You find for example for a lot of turntables huge owners "recommendations" but this chapter is completely denied. Based on my information, most of all modern turntables (no matter which pricing) can't hold proper speed. The reason is very simple: Maximum Profit. If you look at it from the pure standpoint of an engineer without any audio perspective – free from audio pre-knowledge and history - learning from scratch about mechanics and static and dynamic behavior in moving objects, you’d find that a lot of designers have simply not done their homework.
Who is interested to tell others "Hey, I spent 35k for a 3 motor unit but it runs wrong each day differently?" It is much more easy to keep the own "reputation" as a "serious, experienced audiophile" and say "Mine is right..."
I think, you won't get much - honest - answers. That experience - or learning - is something you will have to do on your own ...

The experience you describe goes beyond simple speed stability issues since most turntables of repute are within reasonable limits.

Your controller switching speeds on a whim is a reliability issue and there have been quite a few cases discussed here and on other forums?
One possibility I would consider carefully is static discharge during handling and operation of the controller. If you have a power block with an external earth binding post nearby, it might be helpful to briefly "ground" yourself as a precaution against damage each time you operate the turntable?
If your supply is already damaged I'd be inclined to get it checked by the manufacturer. No point in suffering any longer! :(
Hope this situation improves.

As moonglum says, static buildup can be an issue. I never had stabilty problems, but the controller on my TW Accustic Raven one, suddenly switched to about 300 RPM, luckily, not with a stylus on the record, or that would have been toast. It was indeed due to static build up and the unit was replced, free of charge, with no quibbles, even though it was 3 years old, now that is service. I don't think spending money on kit prevents maintenance issues, perhaps it should, it improves quality and hopefully, after sales service.

One other thing to try, I found using a good, after market power cord, a lessloss, made a big difference to sound quality, which rather suprised me. I thought if one bit of kit would be immune to a better power cord, it would be turntable controller, not so.

I base my speed opinions on sound...if it sounds good (not warble intensive) it's good.

Syntax is right.