c# – Visual Studio debugger “Just My Code” optimization excludes all my code

Using Visual Studio 2019 for a C# app.

I reopened and old project of mine, and during debugging, my breakpoints would not be hit showing the message “no symbol have been loaded for this document”.

Under the modules windows, I found one of mine -> “Symbol Load Information”; it reads

Skipped loading symbols. Module is optimized and the debugger option ‘Just My Code’ is enabled.

I can load it manually, or disable “just my code”, but I want to do neither.

Why are my files now excluded by the “just my code”? How could I mark these files as mine again?