Checkout problems since beginning of September

We’re having the issue since August 31st and we lost more than a 100K in sales. We are still having the issue and Shopify doesn’t have a clue. It took almost 3 weeks for them to finally acknowledge the issue. On sept 18th, I received an email from support that the issue was fixed, as they rolled back an older version. Our conversion rate really improved for 4 days, and then back to square one. I have a friend that has a Shopify store that has the exact same issue as well