Hi bro. I have a very similar problem like this one only. My wifi keeps disconnecting or it just says "Internet not available". And it is particularly happening in my Galaxy J7 pro only. Mine is also an optilink router. Can you please tell me a solution for this other than changing the router. Is there any setting in Optilink router to solve this issue? Please do answer. This problem is irritating me from months and i found no solution.