So I just got the wife a caliber bossnut and after about 15 miles total, the shifter just stuck wouldn’t go up or down a gear took it off and the cable was wound up in the spring as a result of it taking ages to drop a gear from the lowest gear, got it in the stand when I got home cycled through the gears and it did it again sorted it again and it’s done it again!

Any one else had issues with these shifters?

To be clear then: this is a new bike?

And the cable is winding around the spring inside the shifter? Not the visible spring in the mech. And you have had the cap / lid off the shifter to see what’s going on?

Welcome to the forum ads.👍

Nice choice of bike too!

Sounds like a shifter issue imo and I’d be tempted to take the bike back to go outdoors and demo the problem to the mechanic on their bike stand in the shop.

My guess is you have stiff pivots in the mech (not unheard of with recent Sram mechs), which aren’t allowing it to drop down the block. This allows the cable to go slack, pop out of it’s housing in the shifter, and tie itself up in the spring etc.(i’ve seen similar happen when shifting without pedalling, and i’ve seen enough mechs that won’t drop down the block to make me think this).

SX Eagle is, from experience and from research, utter crap. Google it. ZyroFisher are currently replacing warranty claims with NX parts
The first rear mech we saw lasted less than one ride (gentle trail ride, mature lady rider) when the mech snapped off at the main pivot. On examination the entire thing is plastic, including the snapped mech knuckle. The adjuster screws are self tappers direct into plastic. The jockey wheels are cheap and flimsy. They really are very poor indeed. There’s reports in the US of virtually all of it being sent back for warranty replacement. Certainly Shimano Altus is better made.