After upgrading to Niagara G3 3.8 (from 3.7), nested PxIncludes now only partially load and very slowly. They are not all entirely missing. After a screen refresh, most will load except for a random few. Also, they may load all at one moment but not the next. The same Px file in version 3.7 loads faster with nothing missing.
Niagara G3 / AX version 3.8
PxInclude caching is disabled by default in 3.8.
This issue was addressed with the release of an updated bajaui module - version 188.8.131.52. This version re-enables PxInclude caching. Download it here.