Rock in D minor (variant) — fingerstyle
As on the catalogue's A minor (variant) grid, F's bass note is carried by the same finger (the index) that also holds the barre across two other strings: if that finger eases up even slightly, the thumb's bass note disappears, unlike Dm, Am and C, where the bass note is either open or held by a dedicated finger.
Tips
On F, check that the barre holds firmly before even worrying about the thumb.
On Am, use the open string to lock the thumb's tempo with no left-hand constraint at all.
If you already know the catalogue's A minor (variant) grid, that same bass landmark applies here identically.
Chord progression — Dm
Bar 1
Dm
i
Bar 2
F
III
Bar 3
Am
v
Bar 4
C
VII