t3-assets folder keeps creating new .js and css files over and over again

Hi there
I have had T3 installed for about 6 months now and working 100% OK.
Sometime in the last 10 days, I noticed my Akeeba backups suddenly were getting larger and larger every day.
I discovered that the t3-assets folders for css and js had well over 500MBs of files.
Then I checked the date and time stamps.
In some cases new .js files are being created every couple of minutes.

So every 24 hours I have been manually deleting all the .js and css files.

I have T3 version 2.4.9 installed now. Same problem was happening with version 2.4.8
I have Conservative Caching turned ON.

Do you know what might be causing this problem ?

Regards
Derek.