@9463268 Welcome to the community. For a first time post you definitely came out swinging. You posted suspicions, not facts, and accused Brave of shady business practices. I am all for meaningful feedback but, from my point of view, you posted in bad faith and spit out a fair amount of venom yourself. If you want to be taken seriously, you should support your statements with examples, links, screenshots, etc. of bad behavior by Brave. Right now, most of your accusations are vague and unsubstantiated and are not representative of my experience with Brave ad-blocking at all.
My shields and fingerprinting settings only revert back to defaults on exit if I have clear site and shield settings checked in the on exit tab in clear browsing data. Maybe you have that box checked in all your devices? If not, you may want to open a support topic to see if Brave support or another community member can help figure out what is going on. It is weird that it is happening on all your devices. I think it is probably a setting but without more information, can’t really say. Make sure you fill out the template if you do decide to create a topic: the information requested will help troubleshoot your issue.
Since advertisers are constantly looking for ways to circumvent ad-blocking and filter lists, it is really helpful if you can report instances of ads displaying in the Ad-blocking category. The About topic pinned at the top of the category has some really useful information and instructions for reporting.
Also, if you see a sudden uptick in ads, especially any 3rd-party ads, you may need to update your filter list(s). You can check for updates at brave://components. You can also check which filter lists you have enabled at brave://settings/shields/filters. I think (not sure) uBlock Annoyances is enabled by default. You should probably enable Easy-List too. I think Fanboyz Anoyance list already has Easy-List included.
There are experimental ad-block features you can test at brave://flags. I don’t suggest changing any of the default settings unless you really know what the feature does. Usually you can do a web search to find out more about a particular experimental feature.
Finally, posting links to Brave articles that may help you understand Shields and ad-blocking in more depth. There are other Brave articles out there if you want to do a deep dive but I think these will cover the basics.