sound garbled after restoring save states - all FM sound games affected

[spikemorrissey]

I can save and restore snapshots with no problems on games that do not have the FM sound upgrades such as Alex Kidd in Miracle World, Choplifter

However I have totally garbled sound problems when restoring snapshots on all games in a new game session that utilise the FM sound upgrades such as Wonderboy in Monster Land and Fantasy Zone II. There are quite a lot of games on the Master System that make use of FM sound and the difference in quality is amazing!

All games run perfectly with perfect sound in the initial game session - this issue is only reproduced when restoring a snapshot in a new game session so a serious issue

In the retroarch options I have Master system FM set to auto and Master System core set to Nuked.

Please can you advise
Using a raspberry pi 4 RetroPie Version Used : 4.7.1