This has happened to me as well in 1.14.4, and when I tried to exit the boat there was the lag, and when I finally exited the boat disappeared. I know where it was and whenever I walk over to the location, my walking lags. I tried seeing if I could interact with this invisible boat, breaking it, boarding, etc. and I could not. Like previous comment about it occurring on normal shore, this was essentially where it happened for me.
Edit: Logged off and went back on and then I could see the boat and interact with it like normal, but regardless, was a bit frustrating
Audrey French
This has happened to me as well in 1.14.4, and when I tried to exit the boat there was the lag, and when I finally exited the boat disappeared. I know where it was and whenever I walk over to the location, my walking lags. I tried seeing if I could interact with this invisible boat, breaking it, boarding, etc. and I could not. Like previous comment about it occurring on normal shore, this was essentially where it happened for me.
Edit: Logged off and went back on and then I could see the boat and interact with it like normal, but regardless, was a bit frustrating