My iPad 3 suddenly refuses to hold the very strong (5 bars) 4G LTE signal here at work. The LTE signal is very strong here, my iPad has always had an excellent LTE signal since I activated it a few months ago. Now, it grabs the LTE signal immediately -- five bars -- and gives me LTE speeds. This lasts only for a couple of minutes. After a couple of minutes, it suddenly says **Could not activate data cellular network** and reverts to 3G. This never used to happen, but has been happening for the past several days now.
I've tried resetting network settings, airplane mode on/off, turn wireless off, turn on/off cellular data, hard reset of the iPad, full shutdown of the iPad. Nothing worked.
I've Googled, and this appears to be a fairly common issue without any clear resolution. What's the answer?