An eSIM may stop working correctly on a dual-SIM phone when the wrong line is selected for data, automatic switching moves traffic to the primary SIM or roaming is enabled on the wrong line.
The safest fix is to assign one line to Mobile Data deliberately and test it before changing network or APN settings.
Do not delete the installed eSIM. Removing it can make recovery harder and should only be done when NoveSIM Support specifically instructs you to do so.
Quick answer: Turn on the travel eSIM, select it as the Mobile Data line, enable Data Roaming for it, turn off automatic data switching and keep Data Roaming off on the primary SIM. Then test a website with Wi-Fi disabled.
Why Is My eSIM Not Working on Dual SIM?
Dual-SIM phones separate line status, calls, messages and mobile data. Seeing both lines in Settings does not mean the travel eSIM is carrying internet traffic. Start with the data-only dual-SIM guide if you need to preserve your usual number.
Select the Travel eSIM for Data
- Open the phone’s SIM or Cellular settings.
- Confirm that the travel eSIM is switched on.
- Select it under Mobile Data or Cellular Data.
- Enable Data Roaming for the travel eSIM.
- Disable automatic data switching or cellular data switching.
- Keep Data Roaming off on the primary line.
This prevents the phone from silently falling back to home-carrier data. The wrong-line troubleshooting guide covers that specific symptom.
Refresh the Connection
Turn Wi-Fi off for the test, toggle Airplane Mode for about 30 seconds and wait several minutes after reconnecting. Leave Network Selection on Automatic. If signal remains but data does not load, use the signal-but-no-data procedure.
Check APN Only After Line Selection
Confirm that the plan is active and valid in the current country. If manual APN entry is required for NoveSIM, use data.esim with username and password blank. Do not copy an APN from the primary carrier.
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FAQ
Can two SIMs be active at the same time?
Many phones support dual-SIM standby, but capabilities vary by model and software. Only one line is normally assigned to mobile data at a time.
Why is my phone using the main SIM for data?
The primary line may still be selected or automatic data switching may be enabled. Assign data to the eSIM manually.
Should roaming be on for both lines?
No. Enable it on the travel eSIM when required and keep it off on the primary SIM to reduce accidental roaming.
Should I delete and reinstall the eSIM?
No. Preserve the profile unless NoveSIM Support specifically instructs you to delete it.
Final Recommendation
When an eSIM is not working on dual SIM, correct the selected data line before changing advanced settings.
Disable automatic switching and separate roaming settings for the travel and primary lines.
If the problem continues, record the phone model and safe screenshots of the line settings for Support.
