I can second technion's observations about Microsoft's "24/7" support SLA.
Anyway, as the FAQ answer that I quoted mentions, there are plenty of qualified Proxmox resellers who offer support for folks who are dissatisfied with what is offered by Proxmox Server Solutions GmbH. One reseller explicitly advertises 24x7 support [0]. I expect others would offer 24x7 support if you asked, but don't see the need to advertise it up-front.
Anyway, as the FAQ answer that I quoted mentions, there are plenty of qualified Proxmox resellers who offer support for folks who are dissatisfied with what is offered by Proxmox Server Solutions GmbH. One reseller explicitly advertises 24x7 support [0]. I expect others would offer 24x7 support if you asked, but don't see the need to advertise it up-front.
[0] <https://www.proxmox.com/en/partners/find-partner/all/partner...>