WDT problems with "#include <Heltec.h>"

I was using Heltec ESP32 Dev-boards my ESP32 programs all compiled fine with version 1.15. If I update to versions over 1.15 I get errors with WDT routines. I narrowed the problem down to “#include <Heltec.h>”, If I rem it out WDT routines work fine. Whwt’s happening?