My code reviews of others is often "please add a test", then nothing happens for 3 days, and I get people saying "when will this be done? it already passed UAT

My code reviews of others is often "please add a test", then nothing happens for 3 days, and I get people saying "when will this be done? it already passed UAT! get it moving". then stuff gets merged without tests, and the cycle repeats. Not ALWAYS, and commit/merge absent tests is sometimes required. The shoe was on the other foot a few years back and I was contracted on part of a large/legacy enterprise app product. I could 'fix' a bug, but couldn't always write a test, as I just didn't understand the system well enough to grok what was there. Policy was "you have to have a test". Fair enough. I remember hitting up 5-6 other devs on the team - some of whom had been there for 10 years - to pair for an hour or so to help me write a test. The same people who were blocking the PR requiring a test would not help me write a test. Some were honest enough to say "I don't know how you'd test that". But... it was frustrating. I had a 20 minute code patch (which demonstrably fixed the bug to the PM's satisfaction) take 8 calendar days to figure out how to test. Then a reviewer didn't like how the test setup was done. When they learned it was done with code from a colleague (and not of my own doing) they suddenly liked it and said it was 'clever'. Happy happy days...