It sounds a bit like he's been overwhelmed by the whole potty business and is sending you the message he's not interested. I tended to wait until my kids were good and ready before embarking on potty training. You don't really want to drag it out - it's better to do it all in one go, and get them from diapers to underpants quickly. So if he's not there yet fully - leave him be I would say. No huge rush. He obviously can where he's gone in the past - this is him saying "stop rushing me".
When I did my boys, I simply took them out of diapers, put potties nearby to wherever they were so they could quickly go if needed, and I didn't make a huge fuss. We didn't do rewards. We just treated it as "it's time to use the potty". We gave positive reinforcement (like yay!) but nothing over the top. I think sometimes when we make it into this big deal, they feel pressured.
I know some people use rewards and charts and stars and it works great for them - we are pretty basic here, and I'm too lazy quite frankly (busy mom) so I preferred waiting till I knew they were ready, and made it quick. The thing is, if you just put them in underwear, and they do wet themselves, they quickly learn it's not such a nice feeling and go for the potty next time. But the key to our success was I had multiple potties. I always had one nearby because boys get busy and forget to go.
After they'd mastered that, they used the regular toilet with a potty seat on top.
Good luck :) you have plenty of time!