Anyone notice a regression in 2019.3.1 - Rapid memory increase and UI freeze

I have developers reporting Rider is freezing and rapid memory usage in a specific coding pattern. I am able to replicate and indeed Rider will hang and memory is chewed up, UI freezes then it finally comes good. Afterwards this problem won't happen again. So rather than raise a ticket I want to see if staff or community have noticed a similar regression in 2019.3.1 - as it hasn't been reported on earlier versions:

We have a base class that looks like this:

public abstract class StringField<T> : IField<string>, IField where T : StringField<T>, new()
{
  public abstract StringDefinition Define();
}

This is a 'framework-level' code that our teams include as an assembly reference, then they create a class that contains any number of sub-classes that inherit this base class:

public sealed class Field1 : StringField<Field1>
{
    public override StringDefinition Define()
    {
        return Configure<FieldIds.Field1>()
            .<FluentApiHere>();
    }
}

public sealed class Field2 : StringField<Field2>
{
    public override StringDefinition Define()
    {
        return Configure<FieldIds.Field2>()
            .<FluentApiHere>();
    }
}

What we are finding is when the developer types the following Rider uses up memory in hundreds of MB chunks in seconds and freezes the UI:

public sealed class Field2 : StringField<Field2> {