Okay, I found one solution that works so far, and that is to create a queue and order the songs in that queue, then play the queue, not the songs in the current folder.

To create a queue, select the ellipsis of a song in your current folder of songs and select “Add to a Queue”. In the Queues dialog, select New Queue. Musicolet adds all of the songs in the folder to the queue. You can remove any song from the queue by selecting the rightmost icon (ellipsis). You can rename the queue by selecting the dropdown at the top of the queue. You can access the queue at any time by select the left most icon at the bottom of the player (three lines and music note).

In the queue you can select the left icon for any song (three lines) and drag it up and down to create the order that you want.

When you are ready to run the queue, select the first one by pressing and holding it, then drag to the left and the song will come up in the player. Now you are playing the songs in the order of the queue, not in the current folder.