Hi,
It's not possible to track opening of attachments in case you have embedded these in yoru mail. Instead you can configure Acymailing to not to embed the attachments. In that case the attachments are send as links of your email, which can be tracked. You can disable the embedding of attachments in Acymailing->Configuration->Mail settings under the advanced section.
Regarding the opens and clicks statistics I inform you that I was not able to reproduce your issue. Please check it again and if the issue persists I kindly request that you submit a support ticket through our website at https://www.acymailing.com/support/. This will enable our team to efficiently and effectively provide you with the assistance you need.
Please note that our ticket support is exclusively available for our customers with an active Essential or Enterprise license. If your license has expired or you are using the Starter version, we kindly invite you to renew or upgrade your license prior to opening your support ticket.