This behavior was introduced in 25w06a.
The bug
Players riding boats or any other mobs don't move to the bed properly, which can put the players in dangerous places.
MC-298066
Directly entering a bed from a mount places the player in the wrong place
Resolved
Fixed
0
(Unassigned)
Confirmed
Platform HC
Normal
Player
1.21.5, 25w20a, 25w21a, 1.21.6, 1.21.8, 1.21.9 Release Candidate 1, 1.21.9, 25w44a, 1.21.11
26.3 Snapshot 4
Retrieved
This issue has been fixed in 26.3 snapshot 4.