Just because you download the Portable from the Builds page, doesn’t mean that you haven’t installed anything when you ran it.
It has been the case for some time (a few years at least) that CCleaner Portable has not been truly portable, and if you unzip it onto your computer rather than to a USB stick then it will install itself.
It will create registry entries etc, - Which, among other things, is how you get the recycle bin context menu, and the automatic updating.
A truly portable app does not install anything on your computer.
There are many threads and posts on this forum about it.
@lmaci is our expert user on matters CCleaner portable, and may want to add something better that I’ve explaine it.
In the meantime:
How to Roll Back from v7 to v6.39
Follow ALL of the instructions, particularly about turning off the Automatic Updating.