Hi @alderton and welcome to Mayo Clinic Connect. You'll notice that I moved your message to this existing discussion where @jimb1950@jakedduck1 and @tom1984 are talking about similar issues with bladder and urether obstruction issues. I'd also like to bring @amgracing1@palevsky and @predictable into this conversation regarding their experiences with the supra pubic catheter and problematic urine flow.
Alderton, it's interesting that the issue is problematic at night, while urinating during the day is normal. That would seem to indicate that movement helps and inactivity doesn't, but you need to sleep. Have you considered getting a second opinion?