Might it be better to find yet another instructor at a quiet airfield. Being ATP qualified doesn't always equate to someone with the confidence to send someone solo.
I had in the 70's old Spitfire pilots teach me. Looking back most wasn't good, like no briefings. Good job i was self motivated to learn.
I have had quite academic students at 60, but there was a niggling feeling something could go wrong on their own.
Age is not a barrier for solo, i had a 80 year old i could have sent solo. His landings were perfect, but what if engine malfunctioned. Would he have the speed of mind to deal with it. I never took the chance, he was happy flying dual just for fun.