System lockup using 2.2-RC in a ESXi VM

Hi.
I upgraded from 2.1.5 to 2.2-RC and everything went fine but after an hour or so, the system just locked up. No kernel panic, no message, the system console was unresponsive and there was no connectivity anymore on any interface. The config is the one I had before upgrading and I had no issue at all.
Edit: I even installed 2.2-RC from scratch and imported my config to exclude the upgrade process, same problem.

I use CARP VIP on LAN and WAN interfaces, the dyndns updater, pfSync on a dedicated interface, two OpenVPN clients, one OpenVPN server, and that's about it. Nothing fancy.

There's no crash dump either, so I can't tell you much more. I reverted to 2.1.5 for now since 2.2 locked up within 30 seconds to an hour after boot.