Blood pressure measurement after bilateral lymph node removal

Hi all, I had a bilateral lumpectomy and removal of 3 lymph nodes on each side back in 2023. As a result, I was told to always have blood pressure measured using the cuff on my leg. Several times I’ve tried this - GP practice nurse, an unrelated trip to A&E and also myself at home, and it comes up as something ridiculously high like 180/115. I have chanced taking bp using arm cuff, and it’s normal, something like 110-120/80. Anyone I’ve mentioned this to at the time seems to brush it off, but how are you supposed to know what your bp actually is if there is no way of measuring it accurately? If anyone else has had this experience I’d be interested to know what you do! TIA.