That is indeed a bit strange.
I guess Cricket Wireless needs some manual settings (https://forum.xda-developers.com/google-nexus-5/help/nexus-5-cricket-wireless-t3001205)
I'm not familiar with it, so I can't say too much. Unlikely that it's different in newer versions of the OS, but you could try reslashing the device on the RC or devel channel if you are currently on stable.
Hopefully someone else knows something about manual settings.
You could try asking here too https://t.me/WelcomePlus