Bug Nested prefab losing references when viewing parent but not when viewing child, TMPro Font Asset

I have a nested prefab containing multiple prefabs. When directly editing the lowest level prefabs, all references are correct. When directly editing the highest level prefab (the overall parent) some references are lost. Specifically, the TextMesh Pro font asset reference and the font size revert back to default values.

These prefabs are being imported into the project using two custom packages: one for the asset references and one for the prefabs. This seems to work on a brand new project (with only TextMesh Pro essentials imported) but will sometimes fail on existing projects. I have manually checked if on import there is a change in GUID references, and there is no difference between a working import and a non-working import.

I am assuming this is an issue related to TextMesh Pro because it is only TMP font assets that have this issue; every other reference stays intact.

The odd thing is that this doesn't always happen. I have tested importing the packages into multiple projects, sometimes it works correctly 100% and sometimes it doesn't.



The nested prefab hierarchy looks something like this (overly simplified):

Parent prefab
|_ GameObject
|_ Child prefab
....|_ GameObject

If you directly edit the child prefab you will see everything is working as intended. You will see that objects are referencing items correctly by pointing to assets within the package containing the asset references.

The issue becomes apparent when directly editing the parent prefab. Every reference to a font asset is reverted back to the default variable set in TMP_Settings. This reverts font size to the default value as well.



As far as I can tell, there is no reason this problem should exist. I have checked the .prefab files for the parent prefab in a working import and a non working import, and both are an exact match.

Any information or insight would be very much appreciated. Thank you.

(If further information or a sample project is needed, let me know and I will provide)

 

Extra information:
This is on Unity version 2020.1.6f1, I've checked the changelogs for each subsequent version and do not see this issue fixed or acknowledged.
TextMesh Pro on version 3.0.1, also tried on version 3.0.3 to no avail.

 

Thank you for the fast reply. I submitted a case at the same time I posted this (Case 1288884). The case has more information, a sample project and the custom packages used.

I did notice that when using TextMesh Pro in version 3.0.3 the point size did not revert to default so that part was fixed. The issue still persisted in 3.0.3 with the font asset references.