In case it helps someone else, I had the same issue on my 2006 CR-V. Replacing the coolant temp sensor and fan switch fixed the issue of my incomplete catalyst monitor. The sensors were good enough to not throw a code but off enough that the catalyst test would never initiate. Easy diy, total repair cost was under $100. I had run the “drive cycle” almost perfectly a bunch of times before replacing the sensors with no change. Once I replaced the sensors I literally only had to do one drive cycle and the test completed. Phew!