Problems to reset Beeprint and reflash.

I have some other errors, but I'm not sure if this is a problem with beeprint, so I wanted to go back to the original firmware. I noticed that even after flashing the original firmware, the favicon is delivered by beeprint. I first thought it was a browser cache problem, but it is not (clear cache and fresh portable browser tried). I even completely reflashed the printer firmware and wifi firmware, but the favicon icon from beeprint still appears. Where is this data and how can I remove beeprint completely to see where my problems are coming from? The problems are the following by the way: - After each transfer of Gcode, whether using beeprint or MKS Wifi Cura plugin, the date of the files is 12/02/2018 12:25PM. - Each Gcode contains a "ü" at the end, which is not present when saving to disc. The "ü" makes Cura not want to open the gcode then (that's why I noticed it in the first place). - Some Gcodes have the following at the very end (after printing and after Cura's comments on the settings):

M105
M997
M994
M992
M27

M105
M997
M994
M992
M2
ü

It really repeats until the ever present "ü" appears again. As I said, this may have nothing to do with beeprint at all, but since the favicon is still delivered, I don't know if there are still remnants of it "in the system". Now I tried to flash beeprint again and it does not complete the update. After uploading the webview, the URL "http://PRINTER_IP/update_spiffs " appears and the web server spits out the message "The website is unavailable connection has been reset.". I have to restart the printer afterwards because the WiFi module is no longer responsive. If I simply flash again just the Beeprint FW, everything works with webview as it seems it was never gone. Any help would be greatly appreciated.