Many thanks for your prompt reply, but I had looked at the page and am none the wiser (although in general I find these super clear and think Lawless French and Kwiziq are wonderful).  From memory the English was "You went out even though I wasn't ok with it" both parts seem to be in the past tense.  Sorry, obviously missing something...

Is your question about why the present subjunctive is used instead of the past subjunctive?

There are something like 7 tenses in French, yet the subjunctive really only exists in either present or past tense. Clearly, you can't simply choose the subjunctive in the tense suggested by the entire sentence. The rule is, you use the present tense subjunctive unless you specifically want to denote that one action stopped before the other began.