Chord symbols on fret diagrams are not exported to MusicXML

[jugo6]

When I try to export a score to xml or mxl, plain chords are transmitted, but chords with fretboards disappear. I tried to select all similar chords (without fretboard), copy and paste (to have a line with just chords), but it pastes only one by one (other issue actually).
chord export test.zip

[Jojo-Schmitz]

In the original example at https://musescore.org/en/node/334422#comment-1238698, in one case it even worked for the fretboard diagram, in a case where there were 2 chord symbols at.

It kept only one of the chord symbols though.

[Jojo-Schmitz]

See also #16902

[Jojo-Schmitz]

Actually a Mu3 regression