Connection to Google Big Query sometimes gives error. Not always

Hey Johan, I'm experiencing the exact same thing, but for me its more 60% fail and 40% success. Did you ever figure out what the problem was?

Right now I seem to have the most success sticking my queries in a dataflow and refreshing that. That seems to be more reliable. (Well desktop is 100% reliable, works every time, MUCH faster than online). But I don't like dataflows because of the extra setup it requires. Would love to get an actual solution or a hint at what could be causing this issue.