Hello!
The beacon shutdown zone at the isolation beacon extends further than indicated.
The shutdown zone of other beacons extends to 41 cells from the edge of the isolation beacon, but judging by the description, the zone should be 38 cells.

Can you clarify this point, is this a bug or am I doing something wrong?
There are no other mods installed that could affect beacons.

P.S. If it shouldn't be like this, please check the other beacons, maybe there is a similar situation there too.

Update:
Aha, judging by the description, if another beacon zone (not the beacon itself) is in the shutdown zone, then it will be turned off. Now it's clearer.

Oh, another question, when the isolation beacon is installed, it does not work, and shows that it does not give the effects of modules. In its zone, it turned off all the other beacons, but at the same time it did not give the effect.

Clarification:
If there is another beacon (regular) in the beacon's zone, the isolation beacon turns it off, but does not give any effects itself, even if the regular beacon does not have modules installed, or is not connected to electricity at all, that is, simply if it is placed in the zone of action.

It seems you found the answer to your first question. As for your second question, this is something that I thought was addressed in a previous update. I've released a new update which fixes it.

Yes, I looked into the description in more detail, but it is a bit confusing and complicated, but the table is excellent, I relied on it, so I was surprised when the beacon turned off other beacons in a larger area than 38 cells.
Thanks.