@Ferydaboss 

Hi - I got the same issue like you after upgraded to the latest firmware.  So I played around with the router settings as below, and able to cast to Chromecast within the last 48 hours without any issues so far.  Thought I share it with you.  Good lucks.

In your router settings, go to "Advanced" --> "Network" --> "IPTV/VLAN", then change the "IGMP Version" to V3, and save.

@A.T.1323 

Thanks, will give that a try if it does it again. After playing around with the width and length (bandwith) and after that their support told me to change the MTU size... That was not a good idea (had few very wierd happeni gs when trying to work from home via remote desktop apps, after settimg everything back as it was, it is now working... Altough it is the same settings as before... Really wierd..