Buildship caching old subproject info ... where?

Whenever I do project maintenance such as combining/splitting subprojects, Gradle builds work fine but Buildship has issues that leads to transitive failures of many other subprojects. Example:

The supplied phased action failed with an exception.
A problem occurred configuring root project ‘data_ai’.
A problem occurred evaluating root project ‘data_ai’.
Could not find method api() for arguments [project ‘:api’] on object of type org.gradle.api.internal.artifacts.dsl.dependencies.DefaultDependencyHandler.

The subproject “data_ai” is gone (“api” subproject is still there). Grepping on all files shows that “data_ai” is nowhere anywhere in the project, even considering hidden files and directories. I deleted all .gradle, bin, and build directories - everything except the hidden eclipse files like .project and .classpath. And yet, Buildship is still looking for data_ai.

Usually the error goes away after a few days, indicating that the info must be cached somewhere and was refreshed after a timeout. So where is Buildship caching this info, so I can delete it? I’m all for caching when it makes sense, but this is causing me some pain.

Note: using MacOS 12.1/Eclipse 2021-09 with Buildship 3.1.5.v20210113-0929/Java 17.0.1/Gradle 7.3.1 all current, no betas.

Does deleting the ${workspace_loc}/.metadata/.plugins/org.eclipse.buildship.core directory solve your issue?