Tailwind CSS completion does not work when many files are open in the IDE

Problem

Autocomplete for Tailwind CSS does not work if many tabs are open at the same time 

Tailwind CSS IntelliSense initializes projects for open documents and may request diagnostics for all of them. If there are many open files, this can affect the Tailwind language server and prevent completion capabilities from being registered correctly. Similar behavior has been reported in the Tailwind CSS IntelliSense project: Initialization fails in a v4 project with invalid CSS, refreshDiagnostics() called synchronously after rebuild blocks event loop, preventing completion registration on Windows.

Resolution

Close unnecessary editor tabs and restart the IDE. 

After reopening the project, check whether Tailwind CSS completion starts working again.