[sciurius]

in ChordPro 6.060 they disappeared

You did get a lot of warnings similar to:

"StLouisBlues.pro", line 21, Garbage in start_of_verse: <span color="blue" weight="bold">A</span> (ignored)

If you have content that look like properties (e.g. color="blue") you must use label= e.g.

 {start_of_verse: label='<span color="blue" weight="bold">A</span>'}