This has been happening for too long and it's unhealthy. He won't eat his roaches and will only eat crickets, so when we don't have crickets he won't eat anything. I can't forcefully put the roach in his mouth but it's no bigger than the space between his eyes. Please help how can I make him eat roaches again?
Setup:
50 Gallon Tank
Heat lamp: bright white 70 watt flood light (heats up surface 100-110 degrees Fahrenheit)
UVB: Reptisun 10.0 T5 florescent tube
Both lights 10 inches away from basking spot
Cool side 80-85 degrees and hot side 85-90
Substrate: non-adhesive shelf liner
Your setup sounds good. He's over a year old, correct? Has he been losing weight during this time? If not, then he's probably OK. They do go through phases, especially when they are adults, when they slow down and don't eat much and are less active (not necessarily full brumation). I'd focus more on trying to get him to eat veges when you do as that should start being more of his primary diet than bugs. He may just not like roaches much since he's been ignoring them in favor of crickets for so long. I'd try offering different options for a bit (but still, mostly veges) maybe some black soldier fly larvae or some hornworms and see how that goes over.