Why does Signaltap insist on recompile after recompile?

I always do a full compile.

Locking the changes is not relevant since signaltap indicates that a recompile is requires as soon as signaltap loads.

When I load the design with signaltap the new signals are visible in the signal list.

I have closed signaltap and quartus.

I have deleted the db and incremental_db directories.

I have deleted all directories generated by qsys.

I have checked out the source files from git and rebuild from scratch.

Nothing works.

Quartus/Signaltap is checking something to make this decision.

What is it?