@felmue Thank you for your answer.
I erased and burned the firmware 2.0.4 hotfix version several times and it worked. I don't know why it suddenly started working. I just repeatedly erased and burned it.
@camille-chomant
I think it's the same situation as me.
My M5 DinMeter also works using Arduino IDE. Example programs and homemade programs work well.
However, I burn firmware to use UIFLOW, see the message Successful, and nothing appears on the screen. When I run or download the program from UIFLOW, I get a message saying Successful, but it still doesn't work.