Week 3 CIO no progress

TLDR: coming to the end of week 3 CIO with no discernable progress, any advice?

Hello, we are doing the CIO method with our 5 month old who was showing some good signs of what I thought were readiness (connecting sleep cycles overnight and self settling during the night, but struggling to go down for bed). The first 3 days were promising 25 mins of crying, 11 mins of crying, 19 mins of crying. But, since then we've been anywhere from 3 mins of crying to 30 with no clear reason. When he does fall asleep there has been some improvement in night waking, so he will now sleep through until 1-4am when he wakes for a feed.

Ive put our crying times, total daytime sleep, last wake window data into chat GPT to see if it can spot any patterns I can't, but alas nothing clear. So theres no clear over tiredness or undertiredness pattern.

Initially we were still on a 4 nap schedule with roughly 10.5 hours night sleep and 3-3.5 hours daytime nap total. I have tried moving to a 3 nap day as he was stretching his wake windows anyway, which seems to suit him during the day but hasn't helped at night. Currently we are 2/2.5/2.5/3. With roughly 3.5 hours day naps. This seems vaguely in line with his huckleberry sleep averages of 13-14 hours over the last few weeks.

He is teething which may play a role, but we've been careful to give paracetamol before bed, so he doesnt seem in pain. There has been the odd day of less day time sleep, but never more. Wake up is always 7am, normally 1-2 night feeds.

Current naps are roughly 1.5 hours, 1 hour, 1 hour. So shortening last nap is an option (either by lengthening second or reducing total day time sleep).

Any reccomendedations? Is it worth just giving up and revisiting in a month or two when his sleep is more developed. Thanks in advance.