If you consider that for the cyclical display of the Radiotext history it is necessary to reserve space in the receiver's memory and provide the appropriate function, then it is obvious that this would not be an unwanted behavior, but the intention of the receiver manufacturer. There is no such function or setting in the RDS system itself.
Some receivers keep RT history (artist - title) if RT+ tagging is present.
Most likely, everything is fine and the cause must be found in the receiver settings. The change you registered may be related to the fact that the old RDS encoder did not toggle the RT Type bit A/B, so the same text was constantly rewritten in the receiver. It is correct to toggle the RT Type, it is even necessary for the correct functioning of RT+.
Unfortunately, I am not able to provide you with any further information until I see a recording of the RDS stream, for example from RDS Spy, which is accessible in the Magic RDS with a single mouse click.
