Access via Windows ok, but... When I try to use Mac, it can't be opened

There is some additional config to access vps hosted erpnext via macbook?

There is no specific config which will not allow to use it on macbook.
Check internet connection or Maybe fail2ban have temporary banned you IP.

There can be many things wrong wrong to pin-point issue here. More details can help community member understand your situation clearly

Thanks… I’ll try delete some old certificates… Will let you know!

There have been reported problems with using ERPNext via safari on mac - but it should work OK on FF/Chrome/Chromium

We tried using Chrome… Same error… Still researching… Thanks!