Connection issue with Blink Sync Module 2

[andyb101]

Having frustrating issues with my talktalk router not being able to connect with my Blink Sync Mod2.  The module, which controls my security cameras, works on 2.4 GHz freq.  Whenever I try to pair the router and SM I get the incorrect password error.  (I know it’s correct)

ironically, if I plug in a tp link WiFi extender the SM will connect.  However, it’s hit & miss and is unreliable.

I’ve tried powering off the router, Sync Mod, resetting, persistence with trying to connect all without success.  
My system has previously worked so I’m at a loss why I can’t connect with the router.

Help !!!

[andyb101]

Thanks for prompt reply 

Started a few weeks ago.  I e since received a new router from you but the connection issues persist.

Please note, other devices ie Phones,  smart to etc working fine.

[Chris-TalkTalk]

Hi Andy,

Approximately when did the issue start?

Chris