internet receiver resets

My internet receiver also resets often.  The T Mobile store swapped out the unit.  Said the silver can that I had was an old model with known connectivity issues.  But, the new black unit that he replaced it with is actually worse.  It used to reset once every 2-3 hours, now it's more like 2-3 times per hour.   T Mobile phone support told me first that it was a signal strength issue before the store guy blamed the equipment.  The best signal strength that I can achieve is 2 bars which is weak.  Maybe the phone support guy was right.