Okay. Identified the problem. We had upgraded to kotest v4.4.3, but we were still running kotlin 1.3.72. Surprisingly, this ran just fine on java 8. However, when we upgraded to java 11 everything broke. To get it to work, we have to upgrade to kotlin 1.4.+ or use kotest 4.3.2.
I’m very curious for an explanation of why this happening - just for curiosity’s sake - in case anyone knows.