In your first pic it looks like you don't have the derailleur feathered right, it seems not to be aligned with the cog you've selected. You know that in a friction system correcting that is just a matter of small shift lever adjustments, but if you have an index shifter you might need to adjust the cable tension. If it shifts great on one end of the cogs, check for good cog/cage alignment, and compare that alignment with that on the small end of the cogs. It looks to me like the derailleur might not be tracking accurately across the width of the cassette.
If you are riding with the cage not aligned with the cog, there will be noise, as the chain just begins to work its way over to the next cog.
It could also be that the non-shimano chain doesn't work perfectly with the Shimano cogset, but that's really a stretch IMO. I'd think the PC48 should work.
Road Fan