Optional function tags sometimes don't run even when the tag exists

The bug

When function tags are in a particular configuration, certain functions don't run when you would expect them to. I attached a data pack with the least amount of files needed to reproduce. This configuration has 2 function tags and 2 functions. When loaded it is expected to print two messages in chat, however the observed behavior is that only b:load runs.

#minecraft:load
  -> #c:a
       -> a:load "say load A"
  -> b:load "say load B"

It depends on the names of the tags and functions whether or not the bug will happen!
For example, renaming #c:a to either #c:load, #minecraft:a or #a:load will not cause this bug!

Files

#minecraft:load

{
    "values": [
        {"id": "#c:a", "required": false},
        "b:load"
    ]
}

#c:a

{
    "values": [
        "a:load"
    ]
}

a:load

say load A

b:load

say load B

How to reproduce

1. Download the attached data pack

1. and install it in a world

2. Run /reload

3. ❌ Observe that only "load B" is printed

4. Do one of the following actions

   • Replace "required": false with "required": true

   • Rename #c:a to #c:load (and update reference in #minecraft:load

5. ✔ Observe that both "load A" and "load B" are printed