The oft-repeated question … is the firmware up to date?
New cameras often have quite old firmware installed.
Many firmware updates refer to "general reliability problems" or similar without defining exactly what. See
Latest PENTAX K-70 Firmware Update : Software Downloads | RICOH IMAGING for details.
FWIW, I don't remember my K-70 having this problem in nearly 25k exposures, though my K-3iii suffers occasionally … I just live with it (and cuss), it's too intermittent to expect a definitive repair!
Did the K-70 come with a new lens, or are you using lenses from your older camera?
Whilst the lenses shouldn't be a problem, per se, the contacts may need cleaning