Hi all- long time lurker, first time poster. I recently got a new dual tap kegerator. It came with perlick lo-boy couplers. The regulator seems to be working fine at 10psi, but only one of the kegs is staying carbonated. I’ve switched the couplers and same thing. Air bubbles in the beer line and slow pour until nothing. No gas line leaks. Wondering if I have a faulty coupler?