My OH had his chemo treatment delayed, not due to Covid restrictions, but due to NHS incompetence. He was due for his first infusion the week Boris announced the lockdowns. He got a phone call on the morning saying it was cancelled and they'd get back to him with a revised date "when they knew what they were doing", so they basically cancelled everything without a plan!
Days passed, then weeks passed, and as he'd not heard from them, he phoned a few times, always went to answerphone so he left messages, which they never replied to. After about six weeks, we drove to the oncology dept to see if we could ask in person what the plan was, but when we got there, it was closed and shuttered. So he phoned again a few times. When it got to 3 months and he'd heard nothing, we realised something wasn't right. He phoned his GP surgery to ask if they knew what was happening with the oncology dept, but they said they'd heard nothing. He then phoned the hospital's main reception/switchboard, to ask them, and they told him it had closed permanently and the entire dept had been moved to a hospital in the next county! Nice of them to bother telling their patients wasn't it?
So armed with the phone number for the other hospital, he managed to finally get through to their oncology dept, and yes, everything and everyone had been "centralised" there the week of the first lockdown. Couldn't explain why OH hadn't been told, couldn't explain why no-one in oncology had thought to contact him considering he had been due to start chemotherapy! Apparently, he just fell between the cracks!