Speed problems and router login problems

So, I am having a ton of problems.

First off, I do know tech, so yes, I have reset everything. My problems all started a few days ago. I am experiencing drops in connection every few minutes. I have gigabit internet, about 50% of the time, everything is fine, the other 50%, I have either extremely low download speeds or extremely low upload speeds. By low, I mean to the point where a speed test will show 0-0.5 Mbps for either download OR upload using speedtest.com and on Xfinity's speed test in xFi. Most of the time, I get an error with latency and upload in the xFi test. 

A few days ago, neighbors guessed or cracked our wifi password and I kicked them off (First paused all of their devices, changed the password, they reconnected shortly after, I then blocked the MAC addresses of all of their devices and changed the password again). The next day there was an outage in my area that lasted a few hours (Comcast van worked on fixing it down the road). Ever since that outage, is when my problems started.

The other problem I am having is that when I log into my router via 10.0.0.1 to check logs, devices, settings, etc., I can only log in half of the time. I'll type admin and my password, and sometimes I'll be able to log in, other times it will say I'm using the wrong password. There is no way I am ever using the wrong password though because I'm using autofill data. 

Things I have tried are restarting my modem/router, checking all cables outside and inside, unplugging and cleaning all connections, checking logs (For some reason there are only firewall logs on my router), googling my days away, and contacted customer support. Nothing will help. Could this be purely on Xfinity's end? I am looking for any ideas to try. 

Firewall log for today:

Device MAC:2C:A1:7D:B2:3C:21 , 740 Attempts, 2020/9/25 10:00:14 Device Blocked

Device MAC:A0:6A:44:88:50:8D , 387 Attempts, 2020/9/25 10:00:14 Device Blocked

Device MAC:2A:9F:71:57:79:64 , 23 Attempts, 2020/9/25 10:00:14 Device Blocked

FW.IPv6 INPUT drop , 211 Attempts, 2020/9/25 10:00:14 Firewall Blocked

Device MAC:44:5C:E9:28:2B:AC , 53 Attempts, 2020/9/25 09:57:00 Device Blocked

Device MAC:78:80:38:27:E2:FE , 5 Attempts, 2020/9/25 09:57:00 Device Blocked

Device MAC:64:12:36:71:7B:B3 , 137 Attempts, 2020/9/25 09:57:00 Device Blocked

FW.IPv6 FORWARD drop , 178 Attempts, 2020/9/25 08:44:47 Firewall Blocked

Not sure if this will help, but the top device in the log with the MAC address of 2C:A1:7D:B2:3C:21 has made thousand of attempts within the past few days. The MAC address appears to be an Arris device which I own none of.