Two or more fields are accessed inside a monitor lock. These fields are potentially related and represent a shared state. However, at least a subset consisting of at least two fields are accessed in a location that is missing the monitor lock. Since there is at least one write-access, it incorporates the risk of a race condition.
Enclose the block with a monitor lock.
# Report readonly fields: ignore (default) / report
dotnet_diagnostic.PH_B009.readonly = ignore