Standard shader broken on 2019.3 when loading asset bundle materials

Today I started testing my game with Unity 2019.314f1. I realized that all but albedo properties are suddenly missing in my assets (loaded from asset bundles). These assets were looking normal in Unity 2019.2. In particular I am missing: all reflections (from skybox), normal maps, metal/smoothness maps - only albedo is rendered.
My assets are looking correct when I create a blank new test scene an drop them in. But when I load them from their asset bundle (in game code) the material properties are missing?
Any clue what I need to change, to make them work with 2019.3? Are the corresponding shaders suddely stripped away from the bundles?

Regards,
Marcus

Ups, an editor restart seems to have fixed it…

Today the problem is back. I tried restarting the editor, rebuilding all bundles and re-gernerating baked GI. But now material properties won’t come back. As mentioned above, the albedo map is rendered, but metallic/smoothness and normal maps are simply ignored. Thus it’s not the pink ‘missing material’ surface rendered, but the correct albedo, just without the other properties. I made a player build and the material looks corrent in the player. I am quite sure, that bundle loading (and dependencies) are correct, as they worked perfectly in 2019.2.
Has anyone experienced this before?

After testing a couple of hours now, I suspect this is an editor bug. The only way to get correct rendering form asset bundle materials is to include the Standard shader in the list of always included shaders. This in turn makes game build infeasibly long (< 1 hour). My settings previous however work perfectly in the player…