That shark bite doesn't really like the conversion here.
Any plumbers out there that have seen this type of pipe and fitting? And how are you making the conversion?
Terry sharkbte makes a transition coupling ftom poly to pex. They are a little hard to get. Either model u 4008 or u 4016. The poly side of the fitting is grey, not gold like regular sharkbite. They also make transition pex crimp fittings, that I can usually find at lowes and plumbing supply. They come with rings, but you can use the stainless cinch rings in their place.
There is no reason the Sharkbite should leak, unless the tubing damaged the internal seal, or was not slid on all the way. They work with ALL the cts plastic tubing materials, including pb, PEX, and CPVC. I would be more concerned about the compression tee.
When I re-piped from PB to PEX, I used Sharkbites for temporary connections. AFAIK, the only difference in the PB Sharkbites is the size of the inner support sleeve. I believe PB has a thinner wall diameter than PEX. That said, I used normal Sharkbites as well & didn't get leaks. Not an expert by any means but I'm going to guess the PB has a nick in it or the SB o-ring got nicked.