LB2120 - (4G LTE Modem) Internet disconnects every 10-14 hours

Have recently installed and put into bridge mode connected to an Orbi RB40 as the router. (Firmware on all is up to date) Internet is an unlimited data sim with Three. The internet is intermittent (have to click twice on links to work) and about every 10-14 hours it stops working entirely. The modem still shows connected the Three(4G) but has no internet connection - I have to reset the modem. Any thoughts? I’ve contacted Three but due to the ongoing they can’t get back to me. Does it sound like a Three issue or network issue. Thanks in advance...