All of them, the only place it doesn't do it is Grammarly. On discord, google docs, word, chrome, this box I'm typing in now, it refuses to indent and just cycles through selections. Like right now if I press it highlights the forum post below this text boxWhat app?
First thing I woul try is uninstall keyboard driver and restart. See if the one Windows auto-installs fixes your issues. In addition to the causes listed, I have heard the Teamviewer running can cause this, but I don't recall having this before personally.
Check and see if you have StickyKeys enabled? It can enable itself when it thinks it's needed, so this doesn't necessarily mean that you turned it on, but could cause certain keys (like the tab key) not to operate correctly.