Same too.. I tried to put the simcard to 3G/LTE modem router. It cannot be working at alll.
Got signal, but no internet connections..

Seems like been blocked to use modem router or MiFi

This is the first time I learnt that prepaid simcards being blocked for Mifi/router... Only Umobile did. Anyone knows where is it specified in the TnC?

I bought a LTE modem and put in Umobile but no internet connection. Thought the modem spoilt. Luckily I saw your reply.

Did you mean I need to root the modem router or mifi?
Wao, that's more problem if I swap to digi sim (in the future) become unable to use..

not root, more like a hack.

I bought my modified modem here : https://shopee.com.my/Huawei-B310-4G-Router...2812.1745837007

Based on your link give me one of the seller, it's seems like they slightly twisted the firmware.
But look their screenshot, seems like Unifi SIM (network band 5) not support on that modem. Correct me if I'm not wrong.

Wondering how they know or determine that is modem or router one.. 
If the mac address modem/router itself can determine whether it is modem/router or hp wifi hotspot, then I can say that's the way to trick and change mac address..
I got use U Mobile gilex 30, but the connections seems like not very stable at my area.
Suddenly lost mobile data connections, and automatic change to 3G/HSPA (which is can't load even single whatapps)
And then lost data connections again, go for 4G.. It's seems like frequently change network..

Last few days got try for unifi sim. Unfortunately, my area don't have network band 38 & 40 to support..
Only band 5 can support for unifi 4G connections but my router/modem cannot support network band 5..

so the hack modem you bought, ok or not?
Look gooding if can use on UMobile gx30 / YES 4G datafy for their unlimited hotspot and unlimited data.

if you planning to let go...i will like to test on my location.

According to the info on the page, it's an old worn-out modem. Wonder if it can actually last. Any other alternative?

is the 4g connection really stable for gx30? am i correct in saying, if the modem not support 3G then it would not 'capture' 3G coverage and continue to connect 4g?

i mean, when use in phone, my coverage sometime LTE/4G, sometime it go 3G.

seriously consider to try this modem. i am heavy on tethering to my laptop and my ps4.

want to ask...Does it bypass speed capped?

ok
noted on unlimited wifi tethering.
i just place an order for the modified B310 Huawei...
with antenna of course.

for unlimited hotspot u need some modified unlocked modem or some apps to create virtual environment.
i use a modifed huawei 4gmodem. it can bypass hotspot qouta. but speed is half. like GX30 usually can up to 3Mbps. using this modified modem speed around 1.5Mbps - 1.8Mbps only. but no qouta. if u check from umobile app. the hotspot usage not change at all..