RCON Passthrough not working after changing from installation mode

OS Name/Version:
(Multiple) Pop!_OS 21.10, Pop!_OS 22.04, Ubuntu 20.04.4

Product Name/Version:
AMP ‘Triton’

Problem Description:
RCON Passthrough is no longer working to my servers, I recently had the two Pop_OS! machines in a hybrid + target setup but switched them both to targets and added a controller. After doing this I had to create new accounts on the controller to provide auth and this setup has been working fine.
However It took me a few days to notice that RCON Passthrough was no longer working, of course this was because I never setup a new service key so a tool I use which periodically connects over RCON to run commands was attempting to use my old key for those days.
Now, even after setting up a new Service Login and restarting the two target instances and the controller even RCON Passthrough is not working at all.
Each time a service login is used by the tool in question now(I have generated a few over the last 12 hours) the amp audit log will show this error

Error handling request:[POST:/API/Core/GetActiveAMPSessions] - [ArgumentException]: System.ArgumentException: An item with the same key has already been added. Key: [SERVICE LOGIN KEY WAS HERE] at System.Collections.Generic.Dictionary`2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) [0x000dd] in <c9084dbbb7684502983633fdd54162d8>:0 at System.Collections.Generic.Dictionary`2[TKey,TValue].Add (TKey key, TValue value) [0x00000] in <c9084dbbb7684502983633fdd54162d8>:0 at GSMyAdmin.WebServer.APIService.GetSession (System.Net.IPAddress address, System.String Session, System.String UA) [0x000a3] in <4d2291c82c2a476fb60166fd0b2e8e02>:0 at GSMyAdmin.WebServer.APIService.HandleRequest (m.Http.IHttpRequest request) [0x000f7] in <4d2291c82c2a476fb60166fd0b2e8e02>:0 at m.Http.Handlers.Handler+<>c__DisplayClass6_0.<From>b__0 (m.Http.IHttpRequest req) [0x00000] in <6ba0f115d4834d51b3526e12d15cee09>:0 at m.Http.Routing.RateLimitedEndpoint+<>c__DisplayClass4_0.<Wrap>b__0 (m.Http.IHttpRequest request) [0x00019] in <6ba0f115d4834d51b3526e12d15cee09>:0 at m.Http.Router.HandleRequest (m.Http.Backend.HttpRequest httpReq, System.DateTime requestArrivedOn) [0x000cd] in <6ba0f115d4834d51b3526e12d15cee09>:0

Steps to reproduce:

  • Step 1 Have RCON passthrough working on a hybrid + target setup
  • Step 2 Switch from hybrid to target and then add in a new controller
  • Step 3 Create new service login as controller requires new accounts
  • Step 4 RCON Passthrough no longer working
    Not sure if this will recreate the issue or if something has gone wrong on my end.

Actions taken to resolve so far:
Attempted to generate and use new service login keys multiple times (Same error from above)
Used ampinstmgr repairauth on both targets
Waited approx 8 hours since last failure before attempting again incase of rate limit

I appreciate any help with this issue as a good portion of my income hinges on this feature working.