Hello and welcome!
I believe your problem is related with this PR - https://github.com/BabylonJS/Babylon.js/pull/14584t
You may try to use temporarily (until this PR will be merged etc) some earlier Babylon.js version.
(Seems that the release is done already - Release 6.33.0 · BabylonJS/Babylon.js · GitHub)
Another way - change animation loop mode as described here - Camera Animation bug - #6 by Juancode
Your old code:
BABYLON.Animation.CreateAndStartAnimation(‘deplacement’, cam, criteria, speed, frameCount, cam.position, newPos, 0, ease);
New code which should work:
BABYLON.Animation.CreateAndStartAnimation(‘deplacement’, cam, criteria, speed, frameCount, cam.position, newPos, BABYLON.Animation.ANIMATIONLOOPMODE_CONSTANT, ease);
Hope it will help 