Apple’s efforts to diversify its reliance on Samsung as an iPhone display manufacturer has reportedly hit problems. The Wall Street Journal reports that efforts to get LG Display’s OLED screens into the iPhone production line have hit manufacturing issues. Apple is reportedly divided on whether LG will be able to succeed as the second source of OLED displays for the iPhone.

Analysts have been warning for months that Apple is in “urgent” need of finding another iPhone OLED supplier besides Samsung. Apple currently uses Samsung’s OLED displays for the company’s iPhone X model. The reliance on a single supplier means Samsung controls pricing on the displays that Apple is buying — and there’s no other alternative at the moment.

LG returned to using OLED phone displays for the V30, but the quality of the display wasn’t very good. LG has also been supplying OLED displays for Google’s Pixel 2 XL handset, and it’s been a lottery whether owners get a good display or not. LG is leading in OLED displays for TV sizes, but the company appears to be struggling to bring that experience over to smaller smartphone displays.