This is fixed for the next version.
Please be aware that due to a fix/change to the Scale parameter in version 19.12 or later, this parameter will not be compatible with older versions of Shotcut. Basically, this parameter has to change behavior to keyframe properly. The change in v19.12 was not backwards compatible with projects made in older version. The next version fixes that. But due to the behavior change the scale made or edited in 19.12 or later will not look the same if opened in a previous version. You will need to touch up the scale if you need to open in older version.