The site where you sign-up for the beta also has the rollback information.
Do read the below post once -
I think it will roll back to Nougat 7.1.2 as the latest version of Nougat is required to download the Oreo Beta Preview testing. Do have a backup during the roll back as the data will be wiped.
This was requested by a few users, no official response yet. Do search for the topic in this forum to get more posts on same topic.
Rolled back to 7.1.2 from Oreo beta -
Well, Android is supposed to have apps open in background for quicker switching and is designed to function this way. Many advise against using Task killer applications on Android.
There are ways to kill the tasks in the background. IF an application is constantly running and draining lot of battery, u can use the below 'Background activity manager' method. I always have memory usage of 70% of the Memory / RAM. The OS is optimised to some extent to automatically free memory.
Background activity manager
You can choose which applications you want to allow to run in the background. Like setting the Mail application to continuously run in background and notify you as soon as u get a mail. Else you will get the mail / notification updates only after opening the application manually.
It surely is a good way to stop applications sucking battery and checking for mail/ updates if you have limited mobile data.
Also, Check Settings > Battery > Battery Activity Manager > 'Application' should be added in Whitelist (So it can run in the Background).
PS :I noticed that after each application is updated, It is automatically added to Whitelist !!
Add the application to Whitelist , a few applications will remain open in the background. It depends on the application size. As I mentioned OS is optimised to free memory in background , it could be clearing the background applications.
Stopped using my Nokia 5 until it becomes a "normal" phone again. It hangs to much, it freezes, there are apps that won't oppen!!! HMD is not doing a good job on this phone. It's been more than a month and problems just got worst