The function removeAuctionConfig forgets to reduce _totalAuctionTokenAllocation, leaving the tokens stuck inside the contract.
When an auction is started, startAuction calculates how many tokens this auction will allocate (epochAuctionTokenAmount) and adds them to _totalAuctionTokenAllocation.
If necessary, an auction can be stopped and removed using removeAuctionConfig. However, the function's first if case doesn't reverse everything that startAuction or setAuctionConfig do. It only deletes auctionConfigs and epochs but forgets to remove epochAuctionTokenAmount from _totalAuctionTokenAllocation.
Since the tokens allocated inside _totalAuctionTokenAllocation are not accounted for (i.e., _totalAuctionTokenAllocation is not reduced by epochAuctionTokenAmount), they essentially become stuck inside the contract. This is because on every startAuction, the new auction amount is calculated by balance - (totalAuctionTokenAllocation - _claimedAuctionTokens[auctionToken]).
Auction tokens are left stuck inside the contract.
Manual review
Reduce _totalAuctionTokenAllocation when deleting the epoch.
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