4G shown but not actually working, 3G working but my phone is not always in - in the Silicon Valley!

Question

I have a Samsung Note 2 and was enjoying 4G LTE almost everywhere I work and live.  Since several months ago, the LTE connection near my work is very intermittent or almost useless, even though the phone shows "4G" on the screen.  It usually keeps showing "4G" but transfers too little data to show a meaningful webpage.  If it does go to the "3G" mode, which occurs only some days, data transfer becomes just fine.  Even if 3G can't be faster than "normal" 4G, in my case it is at least usable.  However, as far as I know, there is no way to lock Verizon Note 2 in the 3G mode. 
Therefore, I cannot use Verizon's mobile internet near my work, where I spend most of my days!   It is especially inconvenient when I go for a break or lunch and do not find wifi. 
It shouldn't be my phone problem, since I have no problem at home (and almost everywhere else nearby) to use 4G.  I still have an old unlimited data plan but do not use many GB a month (usually way less than 2GB).
By the way, my work is right in the middle of the Silicon Valley!  Isn't this funny that we have a serious connection problem here?
(Near Orchard Parkway and Orchard Drive, San Jose, CA.)  
It'll be great if Verizon finds/solves any existing problem nearby.  Thanks in advance!

Answer 1

(Just to add a detail)
I have had this problem for many months already.  Before that, there was no problem inside the building.  Now, I have this problem even outside in this flat area.  It is sometimes better (slow but showing a webpage) but usually so bad (stops while loading or just shows a bad connection message).