I messed up original partitions of my R6220 (like I said in another post), but now I restored them from a backup and original firmware works well. The odd thing is that, now, when I run Openwrt (no matter if custom or standard build), it expands ubi partition to EnglishUI. Furthermore the Factory partition seems to be misplaced, causing the "EEPROM data check failed: ffff" error described here. Dumping Factory from Openwrt (with dd or nanddump, seems to be the same...) results in:
0x000000 - 0x0e00b0 FF FF FF FF ... (like the final part of Factory)
0x0e00b0 - 0x100000 data from PrivateData (mtd11 in original firmware)
Checking the Factory partition from U-boot shows that is in the right position (0x2e00000 - 0x2f00000).
Anyone can figure out what's happening?