We have now established that some key data processing steps—namely, the background subtractions applied to the raw data used to generate the magnetic susceptibility plots in Fig. 2a and Extended Data Fig. 7d—used a non-standard, user-defined procedure.
The details of the procedure were not specified in the paper and the validity of the background subtraction has subsequently been called into question.

Retraction Note: Room-temperature superconductivity in a carbonaceous sulfur hydride
https://doi.org/10.1038/s41586-022-05294-9