That sounds like what I've seen on Azure. Mystery weird problems we see, but they don't. Often in the network side. One time we were pretty sure they had a bad interface in a LAG group. Massive packet loss between hosts, but only on certain ephemeral source ports, about 1/8 of them.... Support couldn't find any issues even after a few days.
This was circa 2018 but AWS was so much more stable at that time. Ok, US-E-1 AWS had issues from time to time but they acked them and fixed them