A little confused about your issue~ What's the model number here? Does your modem work properly? Do you mean the router's network often drop? We'd better make sure the modem is working well at first.

Usually, I will enable Guest Network for my friends to enjoy the nework. With guest network, they can't access the web UI of my home devices. Certainly, we need to make sure our friends won't play...

Certainly, we can connect extenders like you mentioned.

How long did you press WPS/RESET button? We should hold and press it for more than 5s to hard reset it. Besides, you may try to clear the cookies of your web browser or change another web browser to...

Hey, you may try this FAQ from tp-link website. https://www.tp-link.com/en/faq-400.html Hope it work for you.

Just as ajharvey explained, it can't keep parental control work with Access Point mode. I consulted this function before with tp-link and got the same answer.