Dang the bad luck. What your hearing is the slack in the push rod to rocker arm. Long term it could cause damage like, any adjustable valve train that adjusted too loose. Short term should be fine and a chance with fresh oil, that it may pump up. These lifters are funny at time. There’s a chance it will pump up and never give issues again. Some lifters make it over 100,000 miles while others less than 20,000. Some people consider them wear items and change every 25,000 miles. I do not.