After creating a new file (Ctrl-N) and then closing and approving Close without saving, each build (F5 etc.) and closing TeXstudio requires Save As again, although no untitled document is among the open ones. Until TeXstudio is restarted or non-existent documents are saved under the chosen name. When saved, the contents of the file are exactly as when the document was closed without saving. If more files have been created and abandoned, each needs to be saved again and again.

Environment

• TeXstudio: 4.2.2
• Qt: 5.15.2 with 5.15.2R
• OS: Windows 10
• TeX distribution: miktex