Downgrading system

In previous versions of macOS and OS X, it was possible to downgrade but in macOS Mojave, Apple made it harder to downgrade to older macOS versions. It would be possible to downgrade to High Sierra or an older version or macOS or OS X, but to downgrade to macOS Mojave 10.14.5, it would not be really easy to do without downloading a macOS installer that is not from Apple which can be modified or unstable or unsafe to use. I have an 8GB USB flash drive with a macOS Mojave 10.14.5 installer but I couldn’t properly upload it somewhere for you to use because it is probably against the rules of this forum and I don’t want to risk being banned. But there is a macOS Mojave 10.14.6 update released a few days ago that fixed some bugs in the original 10.14.6 release. You can also submit feedback to Apple about the bugs you are experiencing in macOS Mojave at https://www.apple.com/feedback

Well, it would be relatively easy to go back IF you had made a bootable clone before upgrading. You could simply boot into your clone, wipe your internal drive, and clone your entire older system back. If you do not have a clone, it is not easy or impossible to go back one or two incremental versions.

And, FWIW, I would never download anything offered by someone I do not know. Aside from that, the rules here do not allow us to post personal information, so you could not do it anyway.