I am baffled.... I honestly am...

I mean, I have seen bubble issues before with poor tubing, or from heat, but this one I am genuinely amazed about. This does look like there is indeed a leak somewhere.

Can it be that your fuel is older than you think, and it was bought in winter time? AKA, that the fuel was formulated for colder season and contains too much volatiles?

I have checked my channel (YT) but I do not have any videos from the time I battled the same issue... I had that issue allready even before the solenoid was introduced. I have myself never really seen it since.

Please do not be too quick to give it up. The solution CAN NOT be very difficult or complicated, but sometimes it is in tiny details. It can be only in 3 things: Fuel composition, heat or vibration.
Although it is generally not recommended to pull the solenoid from its housing, I think it is wise to check if there is not dirt or a scratch-damage in the housing or something like that.

To remove solenoid, best is to twist it when pulling out, to break friction of the O-ring.