There’s something funny about the tab size in the first tab of a session. (A little hard to explain because I’m talking about two different tabs.)
If I open a new connection, and copy and paste code that contains the tab character into the first tab, SQL1, it seems to default the tab size to 8 characters, even though I have it set to 3 in my preferences.
But then, if you open a second tab, and paste the same code, the tabs are the correct size.
See my attachments, both have the exact code pasted into them.