Problem with connecting portals in multi shards server

[LaughingMind]

Hi guys. I run dedicated server with 5 shards, scheme looks like this:

 

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I setup Shard configuration mod 2.0.3 and made connections to every 10 cave entrances/cave exits in every world. My modoverrides.lua looks like this(the same in every shard folders):

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return {
    ["workshop-595764362"] = {
        enabled = true,
        configuration_options = {
            ["Connections"] = {
                ["1"] = { "2", "2", "2", "2", "2", "2", "2", "2", "2", "3" },
                ["3"] = { "4", "4", "4", "4", "4", "4", "4", "4", "5" },
            },
            ["OneWayConnections"] = {
                ["2"] = { "1" },
                ["4"] = { "3", "3" },
                ["5"] = { "3", "3", "3", "3", "3", "3", "3", "3", "3" },
            },
        }
    },
}

The server starts without problems and when I log into the server the mod starts working and set connections to the portals:

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[00:02:03]: Shard Configuration Mod: Synchronizing connection data to slaves
[00:02:04]: Validating portal[6] <-> 2[6] (active)
[00:02:04]: Validating portal[5] <-> 2[5] (active)
[00:02:04]: Validating portal[7] <-> 2[7] (active)
[00:02:04]: Validating portal[1] <-> 2[1] (active)
[00:02:04]: Validating portal[8] <-> 2[8] (active)
[00:02:04]: Validating portal[4] <-> 2[4] (active)
[00:02:04]: Validating portal[10] <-> 3[1] (active)
[00:02:04]: Validating portal[9] <-> 2[9] (active)
[00:02:04]: Validating portal[2] <-> 2[2] (active)
[00:02:04]: Validating portal[3] <-> 2[3] (active)

At this moment everything looks fine, but when I break the Sinkhole for some reason I get two "Validating portal" commands in a row and the second one often changes portal value to -1:

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[00:03:09]: [(KU_84Tfus3l) LaughingMind] ReceiveRemoteExecute(c_gonext("cave_entrance")) @(66.30, -201.16)
[00:03:09]: Finding a     cave_entrance    
[00:03:09]: Found 102350 (1/10)    
[00:03:16]: Validating portal[2] <-> 2[2] (active)    
[00:03:18]: Validating portal[2] <-> 2[2] (active)    
[00:03:22]: [(KU_84Tfus3l) LaughingMind] ReceiveRemoteExecute(c_gonext("cave_entrance")) @(59.02, 233.85)
[00:03:22]: Finding a     cave_entrance    
[00:03:22]: Found 102351 (1/9)    
[00:03:28]: Validating portal[9] <-> 2[9] (active)    
[00:03:30]: Validating portal[9] <-> 3[1] (active)    
[00:03:33]: [(KU_84Tfus3l) LaughingMind] ReceiveRemoteExecute(c_gonext("cave_entrance")) @(17.29, 501.23)
[00:03:33]: Finding a     cave_entrance    
[00:03:33]: Found 102352 (1/8)    
[00:03:38]: Validating portal[4] <-> 2[4] (active)    
[00:03:40]: Validating portal[4] <-> 2[5] (active)    
[00:03:44]: [(KU_84Tfus3l) LaughingMind] ReceiveRemoteExecute(c_gonext("cave_entrance")) @(-281.56, 363.37)
[00:03:44]: Finding a     cave_entrance    
[00:03:44]: Found 102353 (1/7)    
[00:03:48]: Validating portal[10] <-> 3[1] (active)    
[00:03:50]: Validating portal[10] <-> -1[1] (inactive)   

And ususally it sets 2-3 portals of every shard to -1 value and they become not usable, although I setup all 10 portal connectins in the mod. What could be the problem here?