Internal Error - Working with Deliverables

I am experiencing some strange errors and issues working with deliverables in Project Online.  I am able to create deliverables, but it seems that after I "sync deliverables" a couple of times, it results in "An internal error occurred" and I am no longer able to save, check-in, or do much of anything with the project.  I found and used https://ppm4all.com/2017/02/16/solved-cannot-connect-to-project-online-could-not-load-project-job-failed-retrieve-enterprise-global-template-internal-error-unable-to-open-your-project/, which seems to clear the issue and allow me to continue working with the project - but then, the same issue will happen again.  I am thinking it must be something with the stored credentials synchronizing between Microsoft Project and the SharePoint Online site?  Has anybody run into this before?  Any suggestions for next steps?