Chromedriver 91.0.1 setNetworkConditions({offline:true}) with ServiceWorker

[Henry Rose]

I am trying to test out my site's offline behavior using selenium and chromedriver.  I call 

driver.setNetworkConditions({offline:true, latency:0,throughput:0}) returns ok and does not return an error.

However, it appears that this call only sets the network conditions for the main thread not the ServiceWorker too.  I can load pages from my site which not cached by the ServiceWorker when the offline network condition is set.  I would expect to see my ServiceWorker instead display my offline page.  When I try to load google.com, I get an error that the browser is offline like I would expect.  I believe this is showing that the main thread is set offline as expected.

I think this may be related to this chromium bug: https://bugs.chromium.org/p/chromium/issues/detail?id=1068544

Is setNetworkConditions() only being applied to the main thread by Chromedriver?  Is there some way to apply setNetworkConditions to the ServiceWorker as well using chrome driver?

Thanks,

Henry