when I restore my Calendar from archive, Mojave resets it after 5 minutes

I backed my calendar before installing Mojave last week, which was good since Mojave erased a majority of it when it installed.

When I went to restore my calendar from my backup (using calendar archive .icbu file), it accepts the update and works perfectly for 5 minutes, at which time it erases everything that was restored.

Ive tried multiple times with different back ups, always the same issue and it always resets after 5 minutes. it seems very odd that it runs for 5 minutes and only 5 before it resets.

Please help, I have years of backup in my calendar and I had scheduled most of the coming year already.

Macbook pro 15" (late 2013), Mojave.