Had the same experience last year. No thunder and looked extremely close. We were amazed.
I've lived most of my life in TN and familiar with heat lightning.
I just put 7 min 49MB mp4 on anonfile.
Annoying frogs and AC unit in background.
https://anonfile.com/T9Y3sas8nd/7-20-18_at_8.43_PM_mp4