So it seems that some of the viktor domains are not whitelisted on the network you are using. Are you on the company network? If that is the case, can you check with your IT department if they recently changed anything regarding their network policies? You could try switching to a hotspot on your phone to see if the problem persists.
To be able to connect to the platform the following domains should be whitelisted
<dev>.viktor.ai-
api-<dev>.viktor.ai(still used but deprecated) connect.viktor.aisys.viktor.aidevelopers.viktor.aiaddons.viktor.aiviktor-storage.s3.amazonaws.com