If you go to the extension's settings page (moz-extension://[extension-id]/dashboard.html#user-rules) and upload your ruleset you can't download it in other devices because it does not appear on them.
device 1 information:
Windows 10, Firefox 60.0b4 (64 bit), uMatrix 1.3.4, logged in to Firefox Sync, uMatrix has ruleset uploaded from this device
device 2 information:
Android 6.0.1, Firefox 59.0.1, uMatrix 1.3.4, logged in to Firefox Sync, uMatrix has ruleset uploaded from this device
I know Firefox Sync is may or may not related to uMatrix's ruleset storage because it can also use WebExtensions's settings sync.
Exact steps to reproduce:
Log in to Firefox Sync in Firefox on a Windows PC, set it to sync everything
Do the same on an Android phone
From now it's the same on Android and Windows:
Go to uMatrix dashboard\user-rules
click the icon which has a cloud and an up arrow in it
confirm it has been uploaded
check on the other device if the save is here
Since it will not be here, even after days (checked), you can confirm something went wrong
If you go to the extension's settings page (moz-extension://[extension-id]/dashboard.html#user-rules) and upload your ruleset you can't download it in other devices because it does not appear on them.
device 1 information: Windows 10, Firefox 60.0b4 (64 bit), uMatrix 1.3.4, logged in to Firefox Sync, uMatrix has ruleset uploaded from this device device 2 information: Android 6.0.1, Firefox 59.0.1, uMatrix 1.3.4, logged in to Firefox Sync, uMatrix has ruleset uploaded from this device
I know Firefox Sync is may or may not related to uMatrix's ruleset storage because it can also use WebExtensions's settings sync.
Exact steps to reproduce:
Since it will not be here, even after days (checked), you can confirm something went wrong