If your change affects the signature of the patch, the affected instances will be discared and NOT reloaded. A signature change is adding/removing a pin, adding/removing an operation, adding/removing an interface etc. anything that changes the patch from an outside persepective. So for example adding a node, drawing a link, changing a value usually has no effect on the signature. This behavior was indeed introduced with 2021.4.0
From the changelog of 2021.4.1 we can read
No longer generate proxy classes for records - they shall be as lightweight as possible. The reasoning is that we don’t patch inside of records that often. Since they usually pop up as leaves inside of object graphs, the performance impact of the proxy indirection layer can be quite severe.
This change was probably a little bit too harsh, it means that any change inside of a record will not be reloaded but instead the instance will be discarded. We decided to step back on this a little and do so only for records stemming from libraries. In upcoming previews user defined records should behave the same way as they did in 2021.4.0 again - modifications to a record will lead to a reload of all affected instances as long as the signature of the record wasn’t changed.
Hope this sheds some light on the issue.