So it looks like gain is 4-7 times lower then before.
I am seeing this behavior as well. I hit about 65 then took about a 8 month break from it. Started up again about 2 months ago; gains have been absolutely horrendous. Currently 68.1 skill, working on 1QL 90+CoC rugs. For the past month I have seen numerous 0/5 and 1/5 days (in fact today was 0/5). Back when I was doing mediation before 2/5 was considered a 'bad' day. Now if I get 2/5, I consider that an amazing day. According to https://www.dreamsleeve.org/wurm/grinder/ I should be seeing about 50% med ticks which, by feel, sounds about right. Now 20% seems to be the norm for a day if I'm luck. Something got messed up...maybe during caffeine update? I don't know if timelines match up, but meditation definitely changed in the last 6 months or so.