Failure at height issue?

Hello, I have a Taz4 with new extruder head (so basically a taz5).
I have NOT changed filaments, or anything else. But all my prints are failing after around 3 inches of height, they magically come unstuck from the plate and wind up a mess. I have the TAZ 4 glass plate, I have tried abs slush, white glue, hair spray etc. The plate is tacky to the touch now… I have expanded the brim, adjusted the temp of the plate from 50 to 70 degrees, adjust the filament temp up and down as well.
What else can I try? is there perhaps a mechanical problem I should look at?
It used to work, On the same spool I printed successfully, now the identical files are all peeling off. So something is wrong somewhere.
My printer is used to make products, some of these have print times in days so I have yet to catch it actually failing… it seems to wait until I leave the room or look away for a few minutes.

A picture of the failure would be useful. Immidiate suspects would be fillament slipping due to a hobbed bolt clog or improperly tightened idler arm, or heat related electrical wierdness such as if you have the priinter in an enclosure and the control box isn’t vented, or potentially excess drag on the fillment feed path (feeding off a 10lb roll, a pinched feed tube, etc.)

It doesn’t look like anything other than a halted print that got knocked off the table, and then the natural spaghetti you get from extruding with nothing under it. I can post pictures though once I get home.

There is no enclosure. Room temp is around 60 F

If I set it up to print again right after it happens everything starts fine, so that would mean there is no clog or chewing.

1 kilo roll (matterhackers PLA white). No damage to the feed tube. It flows normally until it gets to some height.

Idler arm should also be fine, I can print normally on shorter print jobs (both in time and height).

I am puzzled… and annoyed.