I guess this is general IntelliSense issue on Visual Studio, not on Unity.
Visual Studio’s cache files (including IntelliSense cache) are stored in a hidden folder named “.vs” that is created directly under Unity project folder.
Sometimes, these cache files in “.vs” folder are suddenly broken due to Visual Studio’s issue.
So, if you delete the “.vs” folder while both Visual Studio and Unity are closed, and then open it again, perhaps autocompleting/advice, etc. by IntelliSense feature, may work again (if you are lucky).
Note that if you delete the “.vs” folder, when you open Visual Studio again, all the last opened source code tabs, etc. will disappear, but the original source code is still there, and you can just reopen it again.
This may not always work (depends on luck, because it is Microsoft quality …), but I think it’s worth a try.
Nevertheless you should use the VS version that ships with the corresponding Unity version. In this case VS2022. Using a different VS version may cause interoperability issues.