After an update from Firefox uBlock Origin webext 1.11.3.b2 to uBlock Origin 1.11.5b0 all "My Rules" are lost.

How to reproduce:

On Firefox Nightly Mac 55.0a1 (2017-03-13) (64-bit) install uBlock Origin 1.11.3.b2 in the webextension version.
Have "I am an advanced user" activated and some own "My Rules" configured
Have all settings be migrated in your profiles extension-data folder.

Under Menu Tools -> Addons choose gear icon -> Check for updates.
uBlock Origin is updated to 1.11.5b0.
What is especially remarkable is that the "uBlock origin could not be verified..." message is gone,
so I assume the installed version is the one from addons.mozilla.org and is not the webext version.
Setting "I am an advanced user" is deactivated and "My Rules" are reset to default.

When installing the webext version from here https://github.com/gorhill/uBlock/releases/download/1.11.5b0/uBlock0.webext.zip over it, it takes quite some time, the addon initializes again and the "My Rules" are back again.
I assume the data is migrated again in that case and maybe "My Rules" modifications done after the initial migration are lost.

What to change:

The bug is probably that the webext version is updated to the non webext version (from addons.mozilla.org). That should not happen.
If possible there should be a firefox and a webext version at addons.mozilla.org and updates should not happen between those 2.

Thanks and regards, Stefan