Federated items are not available after upgrading MIP SDK

We have plugin developed using VideoOS MIP SDK 2019

When upgrading it to 2025 version, only items from the server we are connected to (master) are available, items from other (slave servers) are not available.

If we roll back to 2019 - everything works.

If we try 2022 or 2025 - both do not see slave components.

Right now we try to connect to existing installation - Milestone Server 2019.

can this be an issue?

I am afraid to say that XProtect 2019 is too old and no longer supported. Please see this Product Life Cycle -

https://www.milestonesys.com/support/tools-and-references/product-lifecycle/ and please consider to upgrade the VMS to a newer supported version.