Techdows published a story that the Windows 10 May Update is also causing issues in Firefox.

Windows 10 May Update Reportedly causing issues in Firefox

Firefox users report UI and constant crashing after updating to Windows 10 May 2020 Update. Yesterday we reported Google is looking into Chrome issues with Windows 10 2004 reported by users. Google Security researcher says new Microsoft Edge will also be plagued by these issues soon.

Windows 10 May Update Reportedly causing issues in Firefox