This is a known issue. We're not sure what's causing it, but a future update (probably version 2.3.0) will look for any missed memories and award them retroactively. Basically all you have to do once the relevant update comes out is install it and wait for a new campaign day. After the scout does its sleeping/waking animation on the new campaign day, you should find that you have received both the missing memory and any associated badges/achievements/trophies that the missing memory was holding up.
Notes on this retroactive fix
- The fix works by seeing that you have already received another, later memory for that bear and filling in the gap. We know this isn't the earliest possible detection of a missed memory, but it was significantly easier for us to solve the problem this way. Sorry for the delay.
- If the missed memory is the last one for that bear, such that there is no later memory to notice, the missed memory will be awarded when the bear's storyline is complete. Again, sorry for the delay.
- If two or more memories were missed, don't worry; this should fix them, even if the missing memories are back-to-back and make a large gap. However the game will still need to see that you've received a later memory or completed the storyline before it activates the fix.