I'm running vSphere 6.7u3 on a 2013 Mac Pro with the original 1TB SSD, and I get a constant stream of these lost access to volume events quickly followed by 'successfully restored' messages seconds later.
I found similar threads around this issue that pointed towards the ahci driver being problematic; Lost access to volume … due to connectivity issues
I also found a blog posting from William Lam seeming to clear the ahci driver of all guilt after vSphere 6.5u1; https://www.virtuallyghetto.com/2017/07/ahci-vmw_ahci-performance-issue-resolved-in-esxi-6-5-update-1.html
Performance graphs are also showing this internal local SSD with what I consider extremely high read latency numbers as high as 2400ms with an average of 140ms! I expected much better from a local SSD especially when an iSCSI volume hosted on a low-end Synology is showing single digit latency numbers.