Tags in Panelview Showing Error

We have a Panelview 700 Plus 6 connected to a compactlogix 1769-L32E ethernet port. Recently, the i/o network was migrated from DeviceNet to Ethernet. It is using the same port the HMI does. However, customer is experiencing data "blackouts" for the tags on display; that is, tags show "err" instead of the variables current value. The I/O includes 7 Powerflex 525 drives, 3 encoders, and a Flex I/O bank. The network topology includes a ring network combined with a switch, validated with IAB software. The equipment operates all right, except for this nuisance. I think the ethernet channel traffic is higher and and is saturating it. Any ideas on how to overcome this will be appreciated. Has anybody had a similar problem?

Thanks to you all.