My related personal issue very probably have nothing to do with your husbands but I thought I'd report them if only to illustrate how many different conditions can cause the same symptoms.

First, I'm 76 female, suffering for about two years from paroxysmal AFIB. (Take
Xarelto) Per my Apple watch, it is asymptomatic. BP normal.

I've been needing to get up at night to pee ("nocturia") for years, and the greatest nuisance of it is that I find it hard to empty, and if I've let myself overfill, also have trouble initiating flow.

I've had two bladder operations for stress incontinence about 25 years ago. After the second (both urologist and gynecologist worked one after the other), I was instructed to self catheterize - and after every urination! (that is no longer protocol). Good thing my insurance paid for the catheterizes as they were about $5/apiece! I always carried one around, in case I became completely unable to empty - quite a risk for my kidneys. Naturally, I also carried a sterile lubricant and sealed antiseptic wipe.

PSA I stopped some time ago, on my own discussing it with my OBGYN (suspecting it was leading to UTIs), and and am now left with hundreds of sterile sealed catheters! Not an eBay item really, but I remain reluctant to just throw them away given their market value (I'm sure they're even more expensive now).

In any case, here I am with nocturia as described (problem with flow and emptying). (I've gone through periods when the night-time urination occurred a dozen times and the emptying itself took up to five minutes.)

You did not mention taking your husband to be examined for a urologist (or did I miss it?). Prostate enlargement (sometimes cancerous - G-d forbid) often causes the nocturia you describe afflicting your husband.

Just a suggestion and anecdote about my own related health problem. Certainly a different cause but same symptom. (I think I have scarring in the urethra, but as it's not my most important symptom it's at the bottom of my medical todo list.)

I'd suspect I had a prostate problem except for obvious reasons it's impossible (I remember at one time I was living at home, my father had to get up multiple times during the night for a slow flow. His bathroom was between our two bedrooms.