Can't change texture/material properties. Freezes on Save. 5.3.2

Hi

I am very new to Unreal Engine. Been messing around with it for the past couple of weeks.

I’m using Blender to create my level and exporting as usd. In Unreal, I use the USD Importer to import the level in to the USD staging area. When I try to change anything about a texture or material, prior to actually importing the level in to the scene, when trying to save Unreal just freezes and shows Saving packages… 0%.

I have searched the forums and saw some people having the same issue, but no fix really other than recompiling the master material. This works, but only sometimes.

Is there anything else I could try? Or am I doing something wrong?