I think similar glitches have been reported I will explain my part.
I decided to upload one of my matches from Foxy Go Server to the SGF library. You can see it displays the ranks as “?” (I assume this is a visual bug).
https://prnt.sc/106pi93 — I think this is actually caused by the library detecting account ranks. So if you upload a pro game from Ke Jie for example it will display the OGS player Ke Jie 1d rank. As to where if you upload an SGF of a player that does not exist on OGS it will display as “?” Screenshot by Lightshot
Afterwards I opened the game up to review it and when I attempted to change the game information in the review screen it told me this.
https://prnt.sc/106poyo
(The review screen also displays incorrectly same as when I loaded the game up in the non review mode). This also causes all of the tree in your review to disappear as if you had started a new review.
Lastly, in my profile the review gets displayed as null user
https://prnt.sc/106ptdc
Hopefully any of this information will help fix anything.