Might try one arm DB rows, keeping the elbows inline with the shoulders. Keeping in mind the position of the elbows can help to keep the DB in the correct inline position. Or try the same exercise, doing it as a rear raise, with a slight bend to the elbow (one arm at a time). If doing these with a BB, have a wider than normal grip on the bar. As with the face down position on a bench, some may find it interferes with the breathing when heavier weight is used. Can also do this exercise on an incline bench, face down of course.
Reverse pec decks will usually help the rear delt head. If using a Pec Deck, where the elbows are resting on pads, more stress/work will be on the delts, than if the hands on way out when gripping handles. Wide grip Hi-pulls also hit the rear delts very well.
Muscle soreness does not always mean that a muscle in not getting enough work or not being worked hard enough. If you keep improving in muscle size and strength, that is the best indicator. You don't have to be sore after every workout. But you do want a feeling that any muscle has been worked well and time in the gym was worth the effort.
Don't see the connection with TRT (test), but anything could be possible. Good Luck.