My blade might have upwards of 20 hours on it so a relatively simple thing to do is buy a new one and see how it behaves.? I do see the frame bob up & down but it _appears_ to be associated with the weld.? I'll see if I can mark that location to see if it correlates to the bobble.
I'm starting to understand that bandsaws have more components that affect their performance compared to your average (manual) lathe or mill.? They're overlooked because they usually are just used for the first step in machining something -- i.e., cut stock so it can be further processed by something else.? Fortunately they're not expected to be highly precise, but it IS a time-saver (and material-saver) if the cuts are reasonably accurate.
Mark