We couldn’t keep waiting on support. So we finally solved this by updating the build command from yarn build to yarn clean && yarn build.
Support was really unhelpful with after waiting forever and continuing to update the ticket, the only response being:
Thank you for your update here. I would recommend continuing to use the build command yarn clean && yarn build .
I will go ahead and close this ticket for now. If you have any further questions, please do not hesitate to reach out.
This seems not ideal as I understand it we aren’t getting the advantage of cache’d build components. I was also really disappointed at any lack of explanation here. It seems pretty clear this happened with the netlify build engine was bumped and it is related to the cache, but there seems to be no support or desire to look into this in any meaningful way.
We deploy simultaneously to CloudFlare in order to have a backup should Netlify have issues as our sites serve large events and an outage at the wrong time would be terrible. The CloudFlare deploys haven’t had any problems.