Possible solution - see my Edit ##2 below.
Same problem here too. I uploaded about 50 pics and after that its as if the server picks & chooses what pics to make work and the ones that wont work I have tried over and over and it just does not work with them at all. I guess roku must think my family is ugly or something.
While troubleshooting, I tried changing the names of the .jpg files. I cleared my cache. I also tried different browsers (firefox & brave) on my Linux Fedora38 & Windows10 machines. I also tried uploading via google Android as well as my de-googled GrahpeneOS phone. I removed several 8k images to make sure I wasn't hitting a space restriction and I also created a new album (photo stream). All had the same results.
Edit: PS. this is 100% not an issue with the Roku devices. This is absolutely a server issue. Either the responses saying to restart your roku device so u can upload files via your computer to their website while having no interaction with the roku devices at all are bots posting generic responses, or the people responding just have no clue at all and just want to respond for the sake of posting.
Edit #2: Possible Solution - All of my images that were failing were cropped using a phone (android), so I opened them all in GIMP (you can use photoshop as well) & exported them as .png. They seem to have uploaded fine without any issue after that.
