I've been having a problem for about a few years or so. The problem is how my internet repeatedly cuts out. It only happened before for a certain period of time so maybe a few days a week, which didn't really bother me as much for a while. But recently, the problem escalated quite a lot. My internet previously would disconnect for about a second or so before coming back online, although now it repeatedly does this for a longer period of time. I can't recall exactly how long it lasted, usually only from about 15 minutes to a few hours or until I'm forced to restart my modem, which would usually fix it but if not, it would come back sooner or later.

But recently my internet has been cutting out for much longer. A little while ago I started going into my router settings and measured how long it would cut out for, which only said disconnected for about a second before connecting again. Although like I said, this repeated itself almost every 5 seconds with the cycle lasting about 15 minutes to a few hours. Also for the lower bandwidth, it doesn't annoy me as much as this although it's still good to point out. I have an internet 75 plan and I'm only getting about a peak of 10.5 Mbps according to Steam.

I've already tried fixing this multiple times, but it doesn't really seem fixable. A bit of things to note and things I've tried are: I use a CISCO DPC3825 as my internet modem. It's currently in bridged mode since I like port-forwarding with a separate router. That router is the ASUS RT-AC68U, being wired to the modem with a 15FT CAT 5e Ethernet cable. Whenever I download something large like a game, Steam says I'm getting about 10.5 Mbps as stated earlier, but my router's traffic manager says I'm using 80 Mbps worth of bandwidth. Something else to note would be that as I'm typing this, I'm watching my router's network state as every few minutes, the network status changes to either "Your ISP's DDNS servers aren't functioning properly.", "Disconnected", or "The network cable in unplugged". All lights on the modem remain the same state, only with the modem's router ethernet port light flashing sort of rapidly.