Synaptics SMBus TouchPad driver update?

Hi,
I have just upgraded an HP 15-af156sa laptop to 1909 18363.815
However, the touchpad is laggy in that about every 2 secs the mouse response stops for a split second then off it goes again and so on
The current driver is 19.3.31.31 but a support thread it should be 19.5.35.41 or later
I've tried to install 19.5.35.41 but it fails with 'not compatible with this OS'?
I now believe it might be 19.5.35.47 (sp100845) but can't find this driver anywhere!
I've even rolled back to 19.2.4.10 as per the current driver listed on the HP support website for this model but it made no difference
Is it in fact the driver at all and if not then what is the fix?
What driver should I be using and where can I get it?
Anyone else had this issue and if so then what was the fix?
It's even worse than I thought!
The issue is there even for a corded or wireless mouse!!
Even if I disable the touchpad I still get the issue with a corded mouse so not sure now if it's even related to the touchpad