Hi guys. When changing the priorities of the sceneries, the priorities do not
seem to be handled correctly via the Package Reorder Tool. A similar issue
happens when changing priorities via the Content.xml file, in regard to the
Package Reorder Tool. 
A custom
package (let’s call it DD) has priority 1, the MS package has priority 4. Now
when we press the down arrow on the DD package, it goes to the bottom position
even though it should have a lower
priority.
According to my tests,
in this case, MSFS treats the DD package with higher priority, which is wrong.
Now if we press the down button on the MS package, it correctly goes to the
bottom position again. 
And
again, if we press the down button on the DD package, it incorrectly goes to
the bottom of the list, apparently having a higher priority than the MS
package. 
Is this a known bug?
Additionally, when you add custom Priority settings via the Content.xml, those
entries are “passed” to the Package Reorder Tool but in the wrong order (as
above), so even though correct priority values are present, the actual
priorities in the sim are wrong. Stanislaw
Hello @DrzewieckiDesign Thank you for the feedback. We were not able to
reproduce the bug yet but we are having a look. Regards, Sylvain
Let me explain - the main bug seems to be that priorities are defined by the
position on the scenery list - the lower on the list, the higher the priority
is. It is possible however to have the priority values mixed up on the list,
so the one with the highest priority value is not on the bottom. This means
it does not have the highest priority in the sim even though it has the
highest priority value, as on the 2nd and 4th screenshots.
Hello @DrzewieckiDesign Do the packages still show in that order if you
restart the game and reopen the tool? Are you able to reproduce the issue
after your clear the content.xml file? Regards, Sylvain
The packages are shown in the same order after the restart. The Package
Reorder Tool presents the same bug even after removing the Content.xml .
Hello @DrzewieckiDesign I’m still unable to reproduce the problem at the
moment. Are your customers reporting the problem too?