Hi @AnsonHwang,
Hope you are doing well - it's been awhile!
Is the wait in a loop? Standalone waits are not subject to the synchronous time limit, but if you want to continuously call it in a loop, it is subject to the synchronous execution timeout, which is 15 minutes max. See this similar convo about loops - Workflow always fails (suspiciously at around 15 mins!) - #9 by lindakwoo
If you are not looping, it might help to see some screenshots of the configuration