Devices cannot be seen over a couple of days

Hello everyone,
i asked again in the past, about the issue, but i never received back any answer, so i decided to bring it back:

suddenly my connected devices shown as n/a:

and today i noticed that Lora Server does not allow me to change Device EUI:

Is this fact linked to the (previous mentioned) unavailability of my devices?

Thanks,
Nikos.

There are already some topics covering this (e.g. related to frame-counter resets). Creating new topics when your question is left unanswered does not help and only makes it harder to keep the forum organized. Therefore I’m closing this topic.