I explored solo mining twice in the past ~5 month but didnt stick to it because my odds of staking were so low at the time and I never did in fact get my PoR stake until now(I got a few PoS).
I finally got it!
It was about time too, because I was getting close to loosing the research from that first experiment! I feel more confident to keep crunching on my 2 old phones now.
PS: AFAIK, I'm not on a fork, difficulty was pretty high at the time and I was sync'd with the bot