Verification failed...cannot connect to Apple server

Have spent the last 2 months in computer tech torture chamber(!!!!!) trying to get FaceTime to again work ( as it has done for months with no issues on a 7 year old iPad). PLEASE understand, I am trying to get an 86 year old man, who just lost his wife of 60 years the contact and interaction with his family that he desperately needs during this covid. WHY NOW is the tablet...whether that one or my basically NEW iPad getting the error code 'verification failed...cannot connect to apple server.' Between 3 homes and family members we are lost. FaceTime does not work properly anymore and when I tried to wipe my new iPad to give it to him and set up...thinking new iPad would work with FaceTime, now it is locked on that error code! A brand new iPad I still owe 300$ on is now unable to connect to Apple Server??? Very very frustrated! Apparently new update has messed something up...so please tell me what I can do to get my senior his FaceTime back with his family!!!!!!!!