Addon Version
You can get this via running /dominos version in game
10.2.36-cata

World of Warcraft Version
Classic Cataclysm

On a fresh install + no addons but dominos + fresh reset profile, whenever I try to move the class bar on my Survival hunter, it keeps resetting to 0,0.

https://streamable.com/mzx0ia

I've not replicated this, at least on the PTR with a fresh hunter.

I have noticed the same issue with the Classbar on a Retri Paladin on Cata Classic. What seems to 'fix' the issue is disabling Sticky Bars which coincidentally also doesn't seem to work at all.

After a reload or logon the bar would be on the default position again.

same problem, here.
but, just happened on dk, paladin without troubles

same, too.
it happens when only hunter in my case.

Is this still ocurring?

It is but it's hard to replicate it. Some times when I try to move it, it works, and others it's impossible to move from 0,0. I'm pretty sure I'm not changing anything settings-wise either, really feels like a random bug

Is this still ocurring?

Yes, it is (BM Hunter). For some time it helped to reset to Dominos v10.2.33, but this is over since yesterday. You CAN move the class bar with the keyboard's movement keys, though (but slooooooowly ^^). But with my mouse it's the same behaviour like shown in the video.

It seems it constantly sets
["point"] = "BOTTOMLEFT",
in the dominos.lua for my profile. Is this the reference point for the x/y-coordinates?

I can confirm. My Death Knight's class bar is stuck in the left bottom corner.