Pull the shower faucet cartridge out and check it for scale build up or plastic shavings. Turn off the water first and depressurize the water system. The cartridge in the faucet has fairly fine passages and it does not take much to restrict it.
Amateur Radio Operator (KE5DFR)|Full-Time! - 2012 6.7L Ford Crew Cab Dually -2013 HitchHiker Champagne 38RLRSB - Travel with one Standard Schnauzer and one small Timneh African Gray Parrot, retired mechanical engineer