Grove Base Hat has no I2C address

One of my Grove Base Hats is not showing its own 0x04 i2c address - however other i2c devices connected to it can be detected (the 28 in this case):

$ i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- 28 -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- -- 

Also I have a second Grove Base Hat and the i2c address of that one shows up correctly using the same Raspberry Pi. I think the problem might have been caused when I ran the installation scripts for a GrovePi+. At the time, I didn’t notice that that is a different product. Therefore, I wanted to reinstall the original firmware of the Grove Base Hat. I found the firmware here:

However, I don’t know with which command I can reinstall the firmware. Can you please tell me the command for reflashing the firmware?

Hey, I’m having the same problem. Did you end up resolving it?