newbie tubing question on bubbles going up a drop

[GV2]

I put in a 3/16 tubing run this year, my first tubing setup. During a good run last night I noticed that one of my taps had a few gas bubbles shoot up the drop tube whenever a column of bubbles passed through the tee below. None of my other 12 taps/tees behaved this way. Is this OK? If it sounds like a leak to you, would this indicate that the leak is at the tap or the tee? Thanks

[Maplesapper]

Bubbles rising in a drop tube might imply a back pressure situation; but certainly indicates a lack of vacuum.
As a test I would pull the drop off the tree and temporarily plug the tap to seal it.
Do the bubbles continue to rise in the tube or do they pass along the T now ?

If it were me, I would reseat the tap and see what happens.
"t" and taps are cheap, so may as well install new ones while you are there.

[GV2]

thanks for the reply maplesapper. Checking the problem at the tap will be my first step. I will give the spout a few hits with a mallet, then try reseating the drop tube onto the spout. I will replace the tee as the final troubleshooting step. thanks again for confirming that it looks like an issue. All in all, it is pretty cool watching the sap flow on my first tubing system!