I had that problem several times. The male well guarded the the nest… unless, the eggs spoiled for some reason. I would check the eggs with a flash light once a day. I believe my problem was probably water parameters, of some sort. This was with PARVULUS and keeping the low pH stable…. seemed to be a common problem with them.
Checking the brood with a light never seemed to bother him if done quickly. The breeding cave was placed near the front of the tank and facing out for easy observations. If the eggs are fertile, they will check good for a day or two before seeing spoilage…if not fertile they spoil quickly…. in hours.
From my experiences.