VB.NET debugged code changes not saved even though asterisk* was cleared [on hold]

I spent the previous weekend updating my project’s code (ending 7/22/2019). I changed a lot of code, debugged, tested, saved. It was working. I quit VS2017. I made a zip file of my project for safe-keeping. 10 days later I went to add some code for live-testing and ALL CHANGES ARE LOST. They are NOT in my zip file either. The contents of the zip file made on 7/22 shows the last edit to the most recent file as 7/07, same as on the hard drive. I do weekly backups. There are no changes showing in any backups. I scoured my hard drives…no other copies of the file exist except for the duplicates I made to my second HD which have the same, old code. I did make the changes. The files here show changes to this project on 7/21: C:\Users\Magic\AppData\Local\Microsoft\VisualStudio\SettingsLogs\

Any ideas what happened? If it did not save (apparently the case) how was I able to test? If I re-develop that code, how do I know it will not be lost again?

Actually I think this is the second time this happened because last weekend I was fixing code I was sure I had already fixed.

UPDATE: I just made some minor changes and clicked the save button. They were saved. I made another change and exited. It was saved. Two days ago I had to create a new user account due to iCloud Outlook not installing. Apparently portions (unknown to me) of the old user were blocking that install. Maybe they are the culprit?