these are usually physical layer issues, even though you tried a different cable
I would try another one . Also move your ports one at a time to narrow it down to a particular port or port problem , seeing both sides appear to be hardcoded it should work , also you could try setting both sides as "auto" for speed and duplex and see if it goes away. Normally there isn't autonegotiation issues between cisco devices so setting it as auto won't hurt .
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...