MAG250 on Fibre, catchup freezing, sound not syncing

[cooltvspain]

Hi, my client has a Mag250 and they´ve switched to our portal. They have fibre-optic but they are getting sound sync problems and some freezing especially in catchup, some box-sets on demand not playing s well (but fine at our end). They have the latest firmware, and are using an HDMI cable. Does anyone know of anything else they should check? Thanks!

[Bkman2020]

Could be the service.