I had the same issue starting with the original release of 2026 version through at least version 1220.
Had notified support on Dec. 9th about the issue and again when 1220 came out. Was told to be patient (more or less).
Still happening in 1233 (Found that build in a tab on this forum from Andrew).

Issue seems to occur when enter a chord replacement on beat 4 in the Chord Picker tab of the Chord Builder.
(It happens for sure, if you hit [Enter] after picking the chord.)
Whole Chords tab in Multipicker goes blank.

Last edited by Thunderthud; 9 hours ago. Reason: clarification