I think what's causing this is production insisting on remaining on schedule. Based on the timeline, we lost Stuart & Glennon (during the Greece leaving for Turkey stretch) around March 20, and they were back in the Race on the 28th-29th (Bogota sightings).
Legs this season seem to have been filmed on an accelerated filming schedule of 5 days for all three legs each week.
TAR as it stands is a very logistics-heavy show, I could see the decision of not flying teams in till the next country messing up with the production schedule factoring into that choice.
I really appreciate what this season has been going for, but I think the wiser move would have been a temporary pause, especially since we know all the isolated teams return in Belize.
I will never say a bad word about TARUS staying in Europe for whole season I promise.
Now let's not go that far