I encounter that too. I leave my wallet open like 20 hours a day. Sometimes, it shows more than what it's supposed to be. I close and reopen, then it shows the correct value.
reopening didn't cut it for me. i'm staking and all so i don't bother to much right now but its a little confusing having to check the blockexplorer first to know how much coins i actually got. thats all
edit: repaiwallet did it now. what does mismatched spend coins mean. is that a bigger problem? guess not
Mismatched means that is the amount that was corrected by repairwallet to show accurate balances
If ever in doubt, repairwallet first