Entity interpolation while the game is frozen seems to be broken. Prior to 26.3 Snapshot 9, running /tick step resulted in smooth interpolation, but now it is practically instantaneous. See attached video for a demonstration. (If you download and watch the video on a <=120FPS display, you may notice some visual rebounding in the second half; this also occurs in 26.2 and is tracked in MC-311328.)
Linked issues
relates to 3
MC-311092
The first person arm stutters heavily while turning the camera if the game is frozen
Resolved
MC-311124
The player's interaction animation stutters when the game is frozen
Resolved
MC-311328
With a non-default tick rate, particles and entities rebound for a frame upon running `/tick freeze` or `/tick step`
Open
Can confirm.