Cannot Delete Activity Type

Hello, we are using 7pace Timetracker in multiple Azure DevOps organizations, we've decided we wanted to change the activity types we're using, including deleting some activity types.

There are Azure DevOps organizations where the changes were successful, but others where I am getting the following error:

Organization: <my_org>
User: <my_user>@<my_company>.com
Version: 5.50.7.60590
EventTime: 2023-12-10T13:34:31-05:00

An error occurred while handling your request.
 at method: RemoveActivityType
Message: Cannot delete Activity Type cd0690af-8e15-4616-a9e3-f3bcfa0f3d5f. Please contact support.

StackTrace:
   at Timetracker.JointCodebase.BusinessLayer.Config.ActivityTypes.ActivitySettingsProvider.RemoveActivityType(ActivityTypeSetting activityTypeSetting, ActivityTypeSetting replacement, Guid projectId, Guid userId) in C:\a\1\s\TimetrackerOnline\TimetrackerOnline.BusinessLayer\Config\ActivityTypes\ActivitySettingsProvider.cs:line 78
   at Timetracker.Web.Controllers.ConfigurationController.DeleteActivityType(Guid deleting, Nullable`1 replacement) in C:\a\1\s\TimetrackerOnline\TimetrackerOnline.Web\Controllers\ConfigurationController.cs:line 2073
   at lambda_method3831168(Closure , Object , Object[] )
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Logged|12_1(ControllerActionInvoker invoker)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)

Through inspect element, I can see that a POST request is sent to "https://<org_name>.timehub.7pace.com/Configuration/DeleteActivityType"

I've found a very old thread with the same issue: https://support.7pace.com/hc/en-us/community/posts/360023915552-Unable-to-delete-Activity-Type

But the solution provided was that a fix was deployed in the following version of 7Pace. Since we're using version 5.50.x we're already using a much later version.

Please advise, thanks.