"Then I would select a group of photos (including the photo I used to turned off lens corrections), click on the Sync button, make sure that enable lens corrections was turned off and click apply."
This sounds like you make a mistake in the sync dialog settings. If you disable lens corrections for one photo, and then want to sync that across multiple other photos, then you have to check the lens corrections checkbox in the sync dialog. This may sound odd, but it is logical: you want to sync whatever is in lens corrections, including a checkbox that is unchecked. Unchecking the lens corrections checkbox in the sync dialog means you won't sync any lens corrections settings!
Another way of doing this is select all the images, then toggle the little switch in front of the Synchronize button so it becomes Auto Sync. Anything you do now, so including disabling lens corrections, is synced automatically. Do not forget to toggle this switch off again after you're done!!!
Finally, you can disable lens corrections on import as follows. Disable lens corrections for a photo, then save this as a new preset (do check the lens correction box in the preset!). Then use this preset either as camera default or apply it on import.
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