Flat tappet cams are a gamble....

They are case hardened and sometimes maybe one just didn't get fully treated? dunno

One time I did 3 engines the same and used they same cam for all 3...

two of those went bad in a month the other was fine....pulled the 2 bad ones and sent them back and I got 2 new cams of those of which 1 was bad....one engine got a cam 3 times before I went to something else... All the cams were Speed Pro's (sealed power)

The lobes that went soft were either #1 or #8 none other? I have used every lube other than axle grease....may try that sometime....

There is no nothing to say it won't happen again....Just makee sure you do exacty as the cam instructions say for installation and breakin so atleast the warranty will be good....