Now, why on earth would you go and do such a thing.. So now, even if they aren't aware the plan is out there.. They do now and can decide to abandon it and or seek out the insider that leaked such..   This is why we can't have nice things.. At least wait for further information before do anything..
Using wireless? Get a PC.. Connect via cable.. Try again.

Try clearing your browser's cache...

u gotta be clearer about it.
router cannot access modem, no connection... or yr microsoft device cannot access router?
can ANY device access the router wifi?

if yr device cannot access wifi, could be it is too far away, or wrong settings.
if no device can access the router, possibly it's a router problem - that tplink router is problematic, we know.... like rebooting 5 mins when u were trying...

btw... did the unifi guys install for u, all good then but now no good... or u just got it to DIY?

tell yr story completely, then only people can understand n help properly.
if not... all guesswork, trial n error...

u shud be able to log into the router like any router with correct id/pw..

looks like a TP link router issue.

i suggest u post again in below thread... ask the TPlink sifus for help.
https://forum.lowyat.net/topic/4497511/+220

i junked that router on day1, replaced it, happy ever...

oh...??

that means u dun hv the right ROUTER id n pw.

didn't the installers give u?

if default, it's default. if they changed during installation, u need to get them... they did not give u??

if no... u gotta call or livechat to get them.

4 pairs of id/pw... for... router-modem access, router setup, wifi, unifitv... u need ALL 4 PAIRS.