pam127 wrote Found out that most ISPs provide CG NAT SIM card access to the internet. This means you do not have a public IP and therefore you cannot forward ports to make Netatmo work. Looked in...

That seems like compatibility issue. Try change the wireless security type on the tplink router.

Install the latest the firmware. If the problem did not occur at the beginning, reset the router. Contact tplink support if problem not fixed.

There is version 1 and 2. V2 has more advanced feature, such as homecare http://www.tp-link.com/ca/faq-1706.html link aggregation http://www.tp-link.com/ca/faq-1583.html And v2 can handle IFTTT too

Try this beta firmware if yours is a US version 170630 http://static.tp-link.com/Archer C5400(US)_V2_170801_beta.zip

If you buy the tplink in UK, don't need to register any more. " the warranty period will be automatically upgraded to 3 years, and you will no longer be required to register products on our website...