Crank/no start after timing chains

[Jhgrn3]

Does anybody have any experience with a crank/no start problem after timing chain replacement. Rechecked chain with cam locks and crank pin after replacement according to instructions. Battery was out of vehicle for three weeks during repair. Battery tests good but wears down quickly when cranking even with charger connected. Sometimes attempts to start and actually started once but stalled immediately. I’ve read about electrical issues after battery replacement. Reduced power message sometimes flashes when cranking. Two codes triggered from cranking with those items disconnected. Codes won’t clear even though scanner says it was successful. Any thoughts?