Hello,
This is a known issue.
RnD is working on a solution at the moment, but it is planned to be included only in 7.4 firmware release.
Otherwise, suggest to revert to a working firmware version for a while, if that does not create any inconveniences to you.
Alternatively, you could include /etc/init.d/network restart in the startup script in System -> Custom scripts section, to try to automate the service restarts.
Best regards,