I can't do Xfinity anymore

For the past 3 years (yes 3 years!) we have had problems with our X1 DVR cable box.  It lags, it freezes, it gives RDK-03033 errors.  Over and over.   I system refresh and restart the box several times a day. When I call to complain they tell me we need a new cable box.  I have also asked for a newer box so we can watch Paramount+ and Disney + on the DVR box like we can on the downstairs non DVR box.

They have send me a "new" cable box 6 times.  Twice it was the same old box we already have, we swap, the problem continues.  Once it was a non-dvr box like we have downstairs.  Twice it was a dvr box OLDER than the current one. They tell me they are sending a NEW box repeatedly and I get nothing whether I order at the store, on the phone or through the TV when it tells me my equipment is too old to run certain apps.  I have gone into the Xfinity store at least 3 times to be told they don't have newer boxes and give me the same one I have or an older model, or they "order" one that I never get.  Our downstairs box works flawlessly at all times.  It's not the signal.  It's not the wiring.  Tried switching upstairs and downstairs boxes and the box doesn't work downstairs.  Customer service says it's the cable box but can't send me a new one. I give up. I have cable for convenience but this is the opposite.