Why my HTC 10 is not switing to HSPA+ when 4G coverage is not available?

[AC Question]

Hi guys,

I got the HTC 10 last week. I noticed that when i switch (or the coverage of 4G is weak) to 3G and i start using any app or browser, the phone does not switch to HSPA +. It always sends and receive data while having the "H" sign rather than "H+".

is it a setting problem? or a carrier issue?

NB that the 4G works perfectly.

 

[belodion]

Perhaps it cannot display the H+ icon. Some phones seem to show only H, despite being in an H+ area.