What is the software version of vSRX?
Could you try this:
Use the following operational command to delete the automatically generated self-signed certificate:
clear security pki local-certificate system-generated
After you delete the system-generated self-signed certificate, the device automatically generates a new one and saves it in the file system.
If this also does not help get web access, please provide the complete config along with show log messages.
Thanks,
Pranita