Try switching it to 4G Only i had the same problem with my MR600 but it Actually fixed it.

Hello, So i'm having this problem with my Router Archer MR600 which i bought 6 months ago and at first i thought it supported VPN's but when i started configuring it i found out that the router...

I Don't think the archer MR600 supports IPSec VPN, there's no such option in archer MR600, you could be mistaking, and i have to say i'm VERY Disappointed at you guys and i'm sorry but i Won't be...