@caleb Burks, Thanks for your input. I went ahead and reconfigured all the caching. I will just need to wait and see because I can use (and were able to throughout) my website/checkout without any issue.
@caleb Burks, I have been working through the hosting; that error you see is unrelated.
The original issue is customers would report me over the phone that they are unable to check out. If they are trying to add two different products to their cart, it would not allow. When they’re at the checkout page, they would get bounced back, etc. Unsure exactly what the issues are for them, but I am appreciative of them letting me know as I saw absolutely no issues (I have test purchase many times over the past month).