This seems to have happened always, one can workaround by simply just pushing the call button (phone icon on top right) yourself instead of the link → it opens the same call. this bug is rather annoying though.
also something changed with the integration, since latest rocketchat client release it doesnt open the jitsi call windows in rocketchat anymore but the system default browser instead
Indeed, I have the same problem. Wish this will be fixed in the new build.
BTW, that phone icon on top right should have this text “Video Call” or “Video Conference Call” displayed when mouse is moved over. Also that phone handle should be changed to something else, but different from the video messaging icon. How to fix this?