Issues with FBX import - eviltoast

TLDR: Can you recommend an addon/plugin that helps with FBX issues upon import and export? I found only https://blendermarket.com/products/better-fbx-importer–exporter which is a bit expensive for me, no guarantee it will work either.

Option 2: can you recommend a plugin or addon that recalculates the normals more effectively or that could somehow help with this? Or perhaps you know a workaround?

I’ve used Maya, Zbrush and other 3D software for roughly 5 years but I’ve only started learning Blender for about a month. So I’m not exactly sure which are the best resources or where to find them. From some basic researching, I see it’s common for Blender to mess up FBX imports and exports. Because of that, I’m surprised I can’t find more addons for these situations. I guess I could try importing and exporting an OBJ from Zbrush but this wouldn’t be the ideal workflow.

I’ve followed this tutorial to the letter https://youtu.be/9NjMeAFkm3s and even downloaded the same model used, https://3dsky.org/3dmodels/show/ch33t_chair_2 , however, after setting up the shader, I found ugly seams when applying the normal map. I already tried selecting the model in edit mode and recalculating normals, setting normals from faces, averaging, flipping, etc. and no good results. I also tried marking all edges soft, no luck. I’ve selected the correct UV set as you can see in the shader.

I see the same problem in 3.5 and 3.6.

Thanks