4G to 5G

[MunkyAlucard]

So a couple years ago me and my wife both bought the exact same phone. Galaxy s21. We recently discovered that my phone has 5G but my wife is 4G. How do I fix this? 

[MrGhoul]

Try this,
https://robots.net/tech/how-to-change-4g-to-5g-on-android-phone/

[Robin621k]

You would need to contact your service provider to test the SIM card. If it is not the SIM card, maybe the 5g antennas are bad.

[Ashslayer]

Look at your access point. In settings/ connections/ mobile network/ APN. You need to make hers match yours.

[MunkyAlucard]

We did that and everything matched but no change.

[Ashslayer]

Sorry it's actually access point names not APN

[realaud]

Did you purchase both phones at the same time from the same source?  Do you have the same carrier?  Are the phones locked or unlocked? If one is locked to a carrier and the other not, the carrier may have disabled some settings.  Some years ago, carriers were also charging extra for 5G plans so if one of you had a 5G plan and the other didn't, you would have different configurations on your SIMs.

[MunkyAlucard]

Same phones, same time, same place, same carrier, same price, both advertised as 5G.