fluid fields next_field_name and prev_field_name have incorrect data sometimes

[TomJaeger]

EE7 latest and fluid fieldtype. Why does fluid_content:prev_field_name}{fluid_content:this_field_name}{fluid_content:next_field_name} output some random field names?
I have inside fluid field instances:
text
grid
textarea
textarea
textarea
If i put {fluid_content:prev_field_name}{fluid_content:this_field_name}{fluid_content:next_field_name} inside of each, it is like this:
Prev - EMPTY / This - text / Next - textarea
Prev - textarea / This - grid / Next - textarea
Prev - textarea / This - textarea / Next - grid
Prev - textarea / This - textarea / Next - text
Prev - grid / This - textarea / Next - EMPTY
Bold ones are wrong

[TomJaeger]

Looks like there's some issues with this when using field groups in fluid. Confirmed it existed in 7.4.0 as well.

Following works if there's NO field groups.. needs a good bit of work when there is field groups.
ea4d3e6