about rx 550 i also get init fail and it's gfx804 .
4 x vega rig work about 12 hour then al least one gpu report 0 h rate, restart miner work
6 x rx470 + 4 x rx 580 work for 15min to 30 min then one gpu die , sometimes rig restart itself , workaround it's start miner for each indepent card, for me work from 24 hours