I've check my resources to check for reported issues with missing expenses in QuickBooks Online, but found none.
Let's try doing some browser troubleshooting to fix web page issues caused by the piled up data in the cache. I recommend using an alternate or private window first, before clearing the internet files.
Additionally, you can filter the Date on the Expenses window to reveal those missing transactions. Here's an illustration on how to find them:
Please give it a try and let me know the result. I'll be waiting on standby for your reply and I'm here if you need anything else, @cajodesign.