Help - lens fogging!

What is the definitive solution to lens fogging please?

For context - weather-wise I live in the UK, I have 5 Ring devices (1 Ring Doorbell & 4 stick-up spot cams) - all battery operated as unable to have wired in my property.

I am a long established Ring customer & I have experienced fogging of my Ring devices intermittently but frustrated as currently all 5 Ring devices are fogged so not working. (It has been raining, nothing heavy, & it is not freezing weather either & currently day-light).

“Solutions” tried & failed:

1. Moved Ring device location - made no difference, regardless of being actual location needed for security.
2. Applied lens film - made no difference when tried washing-up liquid, shaving foam or WD40.
3. Wiped lens - made no difference when used a micro-fibre cloth or window/glass cloth.
4. Brought inside to warm device up - made no difference as still later fogs up when later returned outside (where actually needed).

Not yet tried but do not know if any will work:

5. RainX lens film solution? Which RainX product - anti rain or anti mist? (Are Ring device lenses made of glass or plastic as which RainX is supposed to make a difference?).
6. Buy a cover protector? Ring over-hang cover (obscures part of lens view) or silicone device jacket (pain to remove each time need to replace battery).
7. Try to add a silicone moisture sachet inside device? Even if possible - would this void your Ring device warranty?
8. Call Ring support - not hopeful as surely if they had a solution to this apparently well known problem with their devices it would already be listed in their extensive FAQ help guides (which I have already searched)?

I need a solution to stop future Ring lens fogging, as I need peace of mind I have reliable security - if not then I will need to abandon the Ring products & try to find an alternative product to my already heavily invested Ring products.