I was 970 light level with all my gear but now it's showing light level 849 with gear 966 or 970. Light level not showing correctly.
Equip a different chest piece. That one is disabled due to an exploit.
https://twitter.com/BungieHelp/status/1238176242840399873 You likely have the chest piece equipped that is currently disabled. Equip a new chest piece and teh Light should fix itself.