My disc lost connections after NAS installation zyxel 542

HansTZ

Hello

Ive installed 4*4TB and Raid 5 (was suggested) and it worked perfect until restart

then my Zyxel lost all discs.

-Already installed latest upgraded firmware Zyxel NAS542

-Try pull out one disc and the system repaired 1disc and continued beeping

-How to fix this easy with current installation have Seagate Ironwolf4TB discs

-Or can i go back to square one have re-install raid on all the discs

What to do?