In the beginning of Scott Manley's new video The First Commercial Lunar Spacecraft - 20 Years before Israel & Beresheet he takes a moment to talk about recent Falcon Heavy core falling off the boat incident. He advances his theory for what happened, and says that currently there is no evidence to the contrary:
I have an alternate theory, and there is nothing to disprove my idea that the driver of the barge simply didn’t notice this very unfortunate sign on their route home.
The sign shown in the video says 121 feet 6 inches, which is only about 36.8 meters. I don't know if this is a real photograph or just artwork as a visual aid.
Scott Manley is a generally recognized as credible source for space information in general, so if he says there's currently no information to the contrary, then this is plausible scenario.
But that leads me to wonder where there is a height limit of ~37 meters for ships bringing rockets back home, and what obstruction (if any) is causing that limit.