Reproductive behavior of a male t.graeca

[Lorebassi]

Hello everyone, i own a pair of t. graeca (ibera i suppose). Female 40+ yo, with my family since baby, and male bought 3 years ago, he's 13 yo.

They are both in good health (i'm a vet) but since the male arrival, no attempt of mating was observed, neither any kind of interest from the male (e.g. biting). I own other species and i always observed reproductive behavior from males earlier than normally indicated in books, bit this isn't the case.

I don't know if it's possibile that the female does not attract males anymore due to age, but time ago she was with an adult t.h.h that was very violent with her. I think it's a male problem and so my question is if anyone had ever experienced this situation with a male of this species/Age (and size, look at the photo).

My unique other ideas is to perform an endoscopy to evaluate reproductive organs appearance, but i want to know more expert opinions on the breeding topic.

(With any animal species i personally think that collaboration between medical notions of a vet ad pratical experience of an expert breeder can give the best results)

Thanks

Pic https://ibb.co/m9rHOK