Canon PRO-100S series Online Manual page 458

When Encryption Is Enabled, Cannot Communicate with the Printer
after the Encryption Type Was Switched on the Wireless Router
If the printer cannot communicate with the computer after the encryption type of the printer was switched,
make sure that encryption types for the computer and the wireless router matches that set to the printer.
Cannot Communicate with the Printer after Applying MAC/IP Address Filtering or Entering an
Encryption Key to the Wireless Router
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