What do these Dialer codes mean?

Hi,
My friend is having the following problem and I have no idea how to help her, Any suggestions? She has s tablet Dell Venue 7 Model 3741.
On the box it is written 8GB, HSPA, series 3000.
It has a celular chip slot.

Under configuration, preferred network she can choose just 2G or 3G.

Then she accessed the hidden menu with *#*#4636#*#*, it is selected WCDMA preferred.
On the drop down list, there are several options with LTE, like LTE/CDMA or LTE/GSM/CDMA auto (PRL), but any of these options are accepted, the preferred network change back to WCDMA.

Any idea about what is happening?