2x Taxonomy that use CSHS only the last is used

On my site I use two taxonomie.... Lets call them 1 and 2.

Under managed display --- > form the two taxonomy are using SCHS the same way with settings

Parent: None
Hierarchy depth: None
Required depth: None
Force deepest: No
Save lineage: No
Level labels: None
The "no selection" label: - Please select -

With 2.4 all is good.
With update to 3.0 the Taxonomy 1 Term PARENT is now only showing Taxonomy 2 Terms same as Taxonomy 2.
This breaks all my edit pages as taxonomy 2 terms cant be assigned to Taxonomy 1.

My content type has 10x Taxonomies.

Two of theses I assigned CSHS with.

The two are same as your screenshot with only one Taxonomy selected.
Only "Users may translate this field" is unticked

I also use CHOSEN module so I get double display of normal and CSHS boxes.

I know how to hide CSHS box via Chosen visibility, but cant hide the default once.

Any hint?

Do you have 2 fields in a content type that uses the CSHS widget? -- YES
For the field_a, how many vocabularies selected in the field settings? ONE for field_a
For the field_b, how many vocabularies selected in the field settings? ONE for field_b

But only field_b terms are shown for field_a in EDIT under Managed form Display Product selection

On normal Manage display CSHS 3.0 shows the full hierarchy correctly that one was assigned to the content.

your patch seams to work. .. Thanks