Can't make an existing tab private anymore in Firefox 51+ with disabled multi-process mode

[tgitnh]

Today I changed from Firefox 51.0.1 32-bit to 64-bit (same add-ons, same computer). When I right-click on an existing tab, I can't activate "Private Tab" anymore. The tab closes and reopens, but it is not private.
However, opening links and bookmarks with right-click, "Open link in private tab" still works in FF 64-bit.

[Infocatcher]

Already fixed in development version: 5e1371c...6f4aa34
(affected Firefox 51+ with disabled multi-process mode)

[M0ns1gn0r]

The release v.0.2.1.2 is available on Github for 2 weeks, but on the Firefox Add-ons page it's still the version 0.2.1.1. When is it planned to publish the new one?

[Infocatcher]

Was uploaded on AMO right after GitHub...
For now:

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