Spacer background attribute [Release 3.0.2]

I’m in the middle of migrating from 2.4 to 3.0 (on 3.0.2 now), and one of the broken items I can’t fix is the background attribute; I use several Spacer instances in a complex layout, typically,

some sort of layout = column(
widget1,
…,
Spacer(height=8, margin=(8, 0, 8, 0), background=“lightgray”),

Spacer(height=8, margin=(8, 0, 8, 0), background=“lightgray”),
…)

The background attribute is not working anymore. Any suggestions?

3.0.2 documentation for the background attribute is also curious now; it still lists the attribute (under “Inherited from LayoutDOM”), but no description is given.

You’re probably hitting this [BUG] Styles are not applied to model in Firefox · Issue #12633 · bokeh/bokeh · GitHub bug. This was fixed and will be released in bokeh 3.0.3 in a few days.

I’m using Safari, so issue applies to Safari as well. Chrome works however.