add known bugs section in the config references

src/how-to/upgrade/05-config-reference.md

@@ -11,6 +11,7 @@ It is intended for users who:
 
 ## Categories
 
+- Known bugs - known bugs regarding charts deployment and how to work around it, if possible
 - Mandatory (breaking) changes - configuration changes that **must** be applied or services will fail to start
 - Optional changes - new features, enhancements or monitoring/logging options
 - Deprecated - configuration settings that can be removed or omitted, have no impact on the upgrade

src/how-to/upgrade/config-references/wire-server-5.24.0.md

@@ -4,6 +4,16 @@ The following reference was written based on the following [`build.json` charts]
 
 For additional details, you can also read our [release chagelog](https://github.com/wireapp/wire-server/releases/tag/v2025-11-26).
 
+## Known bugs
+
+There is a bug with our `brig` charts failing to deploy in a non-federated environment. If you are running a non-federated environment, to work around this, set the following configuration in your `brig`:
+
+```yaml
+brig:
+  config:
+    enableFederation: true
+```
+
 ## Mandatory (breaking) changes
 
 ### `brig`

src/how-to/upgrade/config-references/wire-server-5.25.0.md

@@ -4,6 +4,16 @@ The following reference was written based on the following [`build.json` charts]
 
 For additional details, you can also read our [release changelog](https://github.com/wireapp/wire-server/releases/tag/v2026-01-13).
 
+## Known bugs
+
+Bug in `brig` for non-federated environments in `wire-server-5.24.0` release has been fixed with this release. You can remove (or set to false!) the following config, if it was used as a workaround in the last release:
+
+```yaml
+brig:
+  config:
+    enableFederation: false
+```
+
 ## Mandatory (breaking) changes
 
 No mandatory changes in comparison to the last release.