AO Multiplier not working with SSRT indirect lighting

[TLSseven]

When I switch the indirect lighting to SSRT, the AO Multiplier option below it doesn't seem to work.
However the tooltip for this option states that it is supposed to 'configure the strength of the ambient occlusion created by SSAO, GTAO, and SSRT'

1.20.1 fabric0.18.1
sodium 0.5.13
iris 1.7.6