Pulsating Biopotential Signal

I am trying to extract biopotential signal output via analog pin A0 of xiao esp32c3 and i am using general biopotential circuit but the output works but shows small pulsating signals although this problem not occurs with other esp32c3 boards

Does this refer to the circuits you built yourself, or do you use our Grove products?
Is there any problem in the process of viewing our wiki?

we have build the circuit by our self