I have same issue after latest CWP panel updates. I live same problem all web sites using Let's encrypt free SLL on CWP panel. Other SSL certs not have this problem. I'm contact with my other friends using CWP and Let's Encrypt SSL. All is have same issue after latest CWP updates.
Maybe this is not Let's Encrypt SLL issue but now we live this problem with CWP panel + Let's Encrypt SSL
I try contact with CWP technical support but I must pay credit for get technical support. Maybe you are too try contact with CWP technical support about this issue.