I was playing normally, when some guy shot me with hornet missiles. I noticed my killfeed hadn't updated for some time, so I ended the session in recursion and resumed it.
At that point I got several callouts, including 1 "100 killstreak".

Which is quite funny, considering the entire session so far only got 84 kills, and I died a bunch of times inbetween too.
Link to saved session:
https://recursiontracker.com/?p=c&c=saved&id=20987

As you can see, I somehow got 2x 48 killstreak, 1x 100 killstreak, 164x "kill brand new player" and possibly some other ones.

But for some reason, it didn't save those to my overall achievements. I only got "100 killstreak" once before, and that should say 2 now, if it had saved them.

So here's the bug report that it sometimes gets a little generous with achievements during a session, without adding them to the overall total (last part is good).