Systematic delays are sometimes unavoidable due to the distributed nature of the ledger. Several reports have highlighted a temporary "state lock" in Smart-Contract-Security-Audits . Increasing your slippage tolerance to a more flexible range can bypass the execution revert. Many rejected calls are caused by the base fee being higher than the max fee.
Running Smart-Contract-Security-Audits on a congested chain requires more patience during the confirmation phase. Always keep your software up to date to benefit from the latest security and logic patches. The transaction might fail because the slippage moved beyond the allowed limit in a second. A conflict between the wallet and the browser's internal storage can cause a freeze.
Layer 2 rollup finality can sometimes take longer than the frontend interface suggests.