There are several things that can cause this:
• The network you’re on might be slow (Check if you're not on a 3G network)
• You may need to set the correct APN. Please check if your APN setting is set to bicsapn
• You may be out of credit, for the first 24 hours we do not block your eSIM but set you to low internet speed (128kbps) so you can add more credit.