A recent blog post https://www.raspberrypi.org/blog/sd-card-speed-test/?fbclid=IwAR2SsnZhK5ccJA8wi2JeE15D978BqsCATvgN0WicQII2-q7d6NEjn2nd07… .
presents a utility. To install open a terminal session
sudo apt update
sudo apt install agnostics
Now under Accessories a new "Raspberry Pi Diagnostics" item appears.
Comment on your results below. Please tell the card and where it came from.
