Clefs appearing for no reason

I am working on parts for an orchestral arrangement, and I suddenly found this interesting issue with clefs (see screenshot). Anyone knows what this might be, how to remove the extra 2 clefs? They are not selectable in write mode, and non-changeable in engrave mode (not possible to change size, colour etc). The player has other instruments, but with no info what so ever in the other instruments (Temple Block, Glockenspiel).

EDIT: the G clef is non-selectable in the score and parts. It won’t be selected even if I press “select all” (!). But the percussion clef gets selected, but is impossible to change.

From Version History Dorico 6.2:

Cautionary and restorative items at repeats. Dorico can now display cautionary and restorative clefs, key signatures, and time signatures at repeat barlines, repeat endings, and repeat jumps.

For example, if jumping back at a first ending to an earlier point in the flow, if there has been an intervening change of clef, Dorico can show the clef at the bar the repeat ending jumps back to, so that the performer has early warning of the change of clef; similarly, when jumping forward to the final ending in a repeat ending, if a cautionary clef is shown for the preceding ending, it may be necessary to show a restorative clef at the beginning of the final ending to remind the performer that the intervening clef change still takes effect.

Dorico shows cautionary and restorative items at repeats by default in new projects.

For existing projects, it is necessary to set the new Clefs and key signatures in repeat structures option on the new Repeats page of Notation Options to Track:

Dorico can only show these items when it is tracking changes of clef, key signature, and time signature through repeat structures in the flow. This option is set to Do not track in existing projects to preserve their appearance.

On the new Repeats page of Layout Options, you can choose whether cautionary and restorative items at repeats should be shown in parentheses. Options for the design of the parentheses can be found in the Repeats section of the Barlines page of Engraving Options, and options for the gaps around and inside these parentheses can be found on the Spacing Gaps page of Engraving Options.

Thank you - spot on!