I was also facing the same issue in the ACA 1.11.0 version project while building my custom extension which was having an import statement "@alfresco/aca-shared/store".
In ACA 1.11.0 "aca-shared" is available as an extension project inside the "projects" folder of the main project instead of npm dependency registered in package.json file. Since it is an extension project so it was having an entry in the "path" object in "tsconfig.json" of the main project, as follows:
From the custom extension, I'll not have access to the specified static path, so I have removed the above 3 entries & added the following 2 entries of the "@alfresco/aca-shared" as follows:
After the above change, I have tried to build my custom extension which was successfully built with the "@alfresco/aca-shared" import. I hope this maybe work in your case too.
Note: Since "@alfrescco/aca-shared" is an extension so must build it before building your extension so that inside dist it has the "@alfresco/aca-shared" folders with their respective built code ready to use in any extension project.