@Pepe wrote, that Turris team will investigate it. I cannot do troubleshooting as those two MOX are productive.
What I don’t understand is, that Turris Omnia doesn’t seem to be affected - I know there are some more users out there using the WLE1216v5-20 inside a Omnia but no one wrote about issues. Having it inside MOX seems to be the rare exception (as you have to solve the heat dissipation issue by adding a fan).