FWIW I've used a 64GB Kingston U3 in both Nokia 6 and 8 without issues.
The card is fresh formatted as media storage in the phone on first use, and files are transferred via USB always. The SD card stays in the phone all the time, to avoid potential issues with computers and card readers.
Did you check the SD card manufacturer's website and the Internet regarding how to spot counterfeit cards claiming to be the particular brand and model you got?
Genuine memory cards break in time too, and can also be defective out of the box. Reputable brand memory cards come with a money-back warranty for 5 to 10 years, typically.
Maybe try a fresh format in the phone and double-check before proceeding?
If you believe the phone is to blame, that is best handled by the official support or at the point of sale.
I hope you get it sorted out.