I think you are saying that he started on hormone treatment in Oct 2018 and the hormones only controlled your dad's cancer for 11 months, which is quite short (for some men, it works for many years) so it seems that your dad has quite an aggressive type.
The way that PSA rise is measured is by doubling time and your dad's doubling time is about 2 weeks which is concerning because it indicates that the cancer is very active, but you know that because the scans have identified new growth .... new growth equals rising PSA.
It is good that they have identified a problem and added the abiraterone, which usually makes the hormones work better. For some men, abi works for a number of years although sometimes it only works or a few months. When it stops working, they will look at alternatives such as chemotherapy or something for the bone mets (Radium 223). If he has a lot of pain from the bone mets, the onco may give him a little bit of radiotherapy; radiotherapy can also be used to stabilise bones that are becoming weak because of the tumours. If dad has a lot of pain, he should be referred to either a pain clinic at the hospital or to specialist nurses such as the local Macmillan or hospice team. Depending on his age, it may also be a good idea for him to speak to the Macmillan / hospice adviser about things like benefits that he can claim.
Does dad get copies of the consultant letters to his GP? Does he have a letter with his diagnosis written on it? Did he have a biopsy in 2018? If so, have a look to see whether he was definitely diagnosed with adenocarcinoma - there are at least 27 kinds of prostate cancer and some of the rarer ones do not respond to hormone treatment so it would be useful for you to know whether that is the case.