Question Max Temp and Printer Shutting Down

What is the problem?
I have been printing PLA just fine with my Octopi setup. I have an older Hictop 3DP-11 (Prusa clone) that is running Marlin 1.1.5. I switched to ABS today and needed to increase the max extruder temp. I updated the firmware to a max temp of 300 (I have an all-metal hot end).

Now, when I set my extruder temp to say 265, the printer shuts off when the temp hits roughly 260.

What did you already try to solve it?
I figured there was an issue with the printer erroring out so I tried setting the EEPROM back to factory defaults and then updating the firmware again, but with no luck. I tried reflashing several times, with no luck, anytime the printer got to 260 it would shut down. The Octopi logs just said it lost communication with the printer, well that's because it shut down the printer.

One a whim, I didn't connect Octoprint to the printer and I manually raised my extruder temp to 260 via the printer's display. The printer went up to 265 no problem, it stayed at 265 for serval minutes. Now I am thinking it's not the printer at all, but Octoprint. So then I connected to the printer via Octoprint, with the extruder temp still at 265 and immediately after connecting, the printer was shut down.

What, in my settings would cause Octoprint to shut down the printer above 260? I have looked and am just not seeing anything that would do this.

I did notice that when I manually change my extruder temp via the display I looked at other settings and I found a setting for autotemp: off and min temp of 210 and max temp of 250. I changed this to 275 before connecting to Octoprint, but the printer still shut off.

Any help would be appreciated.

Logs (syslog, dmesg, ... no logs, no support)
Here is the tail end of my log file.

2020-01-14 22:16:17,169 - octoprint.util.comm - INFO - Changing monitoring state from "Offline" to "Detecting serial port"
2020-01-14 22:16:17,211 - octoprint.util.comm - INFO - Changing monitoring state from "Detecting serial port" to "Opening serial port"
2020-01-14 22:16:17,216 - octoprint.util.comm - INFO - Changing monitoring state from "Opening serial port" to "Connecting"
2020-01-14 22:16:17,224 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-01-14 22:16:17,226 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-01-14 22:16:18,291 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-01-14 22:16:21,590 - octoprint.util.comm - INFO - Changing monitoring state from "Connecting" to "Operational"
2020-01-14 22:16:21,601 - octoprint.util.comm - INFO - M110 detected, setting current line number to 0
2020-01-14 22:16:21,740 - octoprint.util.comm - INFO - Printer reports firmware name "Marlin 1.1.5 (Github)"
2020-01-14 22:16:21,746 - octoprint.util.comm - INFO - Firmware states that it supports temperature autoreporting
2020-01-14 22:16:22,517 - octoprint.plugins.tracking - INFO - Sent tracking event printer_connected, payload: {u'printer_baudrate': 115200, u'printer_port': u'AUTO', 'firmware_name': 'Marlin 1.1.5 (Github)'}
2020-01-14 22:16:24,937 - octoprint.plugins.tplinksmartplug - INFO - ImmutableMultiDict([('checkStatus', u'192.168.1.247')])
2020-01-14 22:16:27,057 - octoprint.plugins.tplinksmartplug - INFO - ImmutableMultiDict([('checkStatus', u'192.168.1.247')])
2020-01-14 22:16:27,407 - octoprint.util.comm - ERROR - Unexpected error while reading from serial port
Traceback (most recent call last):
File "/home/pi/oprint/local/lib/python2.7/site-packages/octoprint/util/comm.py", line 2793, in _readline
ret = self._serial.readline()
File "/home/pi/oprint/local/lib/python2.7/site-packages/octoprint/util/comm.py", line 4932, in readline
c = self.read(1)
File "/home/pi/oprint/local/lib/python2.7/site-packages/serial/serialposix.py", line 501, in read
'device reports readiness to read but returned no data '
SerialException: device reports readiness to read but returned no data (device disconnected or multiple access on port?)
2020-01-14 22:16:27,408 - octoprint.util.comm - ERROR - Please see https://faq.octoprint.org/serialerror for possible reasons of this.
2020-01-14 22:16:27,419 - octoprint.util.comm - INFO - Changing monitoring state from "Operational" to "Offline (Error: SerialException: 'device reports readiness to read but returned no data (device disconnected or multiple access on port?)' @ comm.py:_readline:2793)"
2020-01-14 22:16:28,366 - octoprint.plugins.tplinksmartplug - INFO - ImmutableMultiDict([('checkStatus', u'192.168.1.xxx')])

Additional information about your network (Hardware you are trying to connect to, hardware you are trying to connect from, router, access point, used operating systems, ...)

Does it happen without my plugin enabled/installed? Did you enable the thermal runaway option and it's powering off your printer, causing the connection to die? Are any of the other on error/disconnect options enabled?

It could also possibly be a bad USB cable.

tplink smartplug plugin was the issue. I thought I checked it and made the necessary changes. It pays to check twice I guess. Thanks for the prompt to check it again.