I suspect it is because the other popular instances are getting hammered, it has something to do with them decreasing their API limits and also putting DDoS protection like Cloudflare in place.

I believe after this initial Reddit influx dies down and/or instance moderators scale their services we’ll see it much improved.

I also see that issue with upvotes and even sometimes comment replies.

My posts have been getting eaten. I click to post, all I get is a forever spinner.

STOP EATING MY POSTS!