@mandolyte , This problem is same as that in this ticket. I also had created an issue ticket (see here) to report this problem, the appropriate engineering team is evaluating and investigating this problem. You can follow this issue ticket and add your comments here. I noticed the appropriate engineer has provided some suggestions for troubleshooting, please check with these: Cache's are scoped to a key and a branch, so a cache created on branch-A won't be accessible by branch-B unless branch-A is the default branch. It's recommended that you have a workflow run on your default branch (usually master) so that worklows on other branches will have a cache to restore from.
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