Unexpected pedal line behavior

See 2 attached images + MS file. In order to add pedaling on beat 2 of m. 8, I added a second (hidden) voice.

Issue #1: If I click the bottom note of m. 7, beat 3 (D3) and bottom visible note of m. 8, beat 1 (G3), the pedal extends to beat 2 of m. 8, not beat 1 as it should.

Issue #2: If I click the bottom note of m. 7, beat 3 (D3) and bottom invisible note of m. 8, beat 1 (F2), the pedal mark works correctly. However, if I then try to continue the pedaling in m. 8 by selecting the invisible note on beat 1 (F2) and invisible rest on beat 2, the pedal line goes haywire, extending many measures beyond.

Solutions? Is there generally a better way in MS3 to add pedal lifts on beats where there is no note or rest in the bass clef? I discussed this previously here: https://musescore.org/en/node/228116