Can any one advise regarding the sonoff dimmers.
They don’t keep the % settings that I have set then on Home Assistant.
If I set them for about 80% after a while they dim down to about 15%.
You’re not sitting on the remote are you 
I don’t have that issue. Do you have any automations running?
Is there anything in HA log that says it’s dimming?
Have you looked in the sonoff app? Is there anything in there that looks strange? Any scenes or something?
No I have not activated any scenes or automation.
The Sonoff app looks fine, nothing strange there