Spelling in interchangeable time signatures

Apologies if this is an incredibly basic question, but I’m transcribing some Matthew Locke and I can’t seem to find a way to persuade Dorico to spell the middle minim of a bar of 6/4=3/2 as a minim rather than as tied crochets. Hopefully the screenshot below makes it clear (I’d like to keep the 6/4 for the anacrusis, if nothing else!).

Thanks you! Any advice gratefully received.

Delete the tied Ds. Select the first crotchet rest that appears in its place, hit Enter to invoke the caret, then hit O to turn on Force Duration (you’ll see it light up in the left panel). Then hit 7 for minim and then either type or play the note you want.

You can see from the red time signature flag that (despite the interchangeable signatures) Dorico’s thinking of it in two, and grouping notes in that way.

An alternative to using Force Duration would be to select the barline of the third full bar and enter a 3/2 time signature there that you then hide (from the bottom panel). You’d probably then need to enter and hide a further 6/4 time signature in the next bar.
This method obviously causes more problems if you have some lines in 3/2 and others in 6/4 within the same bar, though it’s worth noting that time signatures can be applied to single staves (either while holding alt when dragging and dropping from the time signature pane, or by using the regular popover but ending with Alt-Enter rather than just Enter).

Thank you so much for such a clear pair of replies! I think I’ll be using the force duration model more, but really useful to have the second spelt out.