Some wifi devices cannot connect to WN300RP, others can

[pzbrawl]

3 mobile devices---a Samsung Galaxy S2 phone, an LG V6, an LG V20---cannot connect to a NetGear WN3000RP extender, whether it communicates with its home router via wifi or Ethernet. The behaviour is the same with each: they hang at getting an IP address.

Turning off DHCP and setting an IP address for the 3 mobile devices allows a  connection but without internet. 

Other devices---PCs, laptops, an iPhone, a Nexus tablet &c---connect fine to the WN3000RP. I've power-recycled it, updated the firmware---no joy.

Are there baked-in incompatibilities between the WN3000RP and some mobiles? Do I need to buy a different extender?

Help please.

[pzbrawl]

I should've mentioned that all three devices connect just fine to the router itself. It's the WN3000RP extender they cannot conect with.

Lots of readers, no answers. According to a majority of Amazon reviews of this product, https://www.amazon.com/Netgear-WN3000RP-Universal-Range-Extender/product-reviews/B0055Y6PUA/ref=cm_c..., it was a mistake to buy the WN3000RP extender. So it appears I need a better extender. On this experience, it won't be from NetGear.