Hi guys, need some advise. I have recently been turboed to 500Mbps.
My hardwares setup are :-
1) BTU - Alcatel Lucent I-240G-P (been with me since 2010 or 2011)
2) Wifi Router - TP Link Archer C7 V2
3) Cable from BTU to Wifi Router - Cat 5E

Problems:-
1) Tested WIFI speeds on Samsung Note 4, Ipad Air, Xiaomi Redmi Note 5 with Ookla on 5G band but could not achieve more than 180 Mbps download Wifi speeds. Have tried contacting TM but the technical department says due to recent upgrades, the speed are still not stable and ask me to be patient and will re-fresh my connections to see if there is any improvement which it did not. - Are my hardwares ready for 500 Mbps and are my WIFI testings accurate?

2) Bought a Cat 6 cable (brand - U Green) but when connected from BTU to Wfi Router, the WIFI connections becomes erratic, sometimes online, sometimes offline. I changed back to Cat 5E and it becomes stable. Is the Cat 6 cable not compatible or defective?
note - The Cat 6 cable was bought online and was quite cheap, maybe that's the problem.