That every program is using a different axis system is a known issue that can’t be fixed. It just exists and we have to work with it.
To make the corrections for these cases, Unreals standard editor mesh importer provides a transform to correct exactly these issues. The plugin does the same on the ImportScene node. Just play with the rotation should solve your issue. **You should NOT need to flip a scale axis. **Also note that in your pictures the object is twisting the other way round (compared to max) cause of your flip.