Usually when some channel gives you instructions to install their channel via developer mode it's because they're violating Roku's terms of service (i.e., they're a shady company). Roku will blacklist anyone trying to use this method to skirt their TOS and will not allow you to enable developer mode anymore. I don't know anything about Channel Pear, but that's probably what happened to you
On the other hand, are you sure you entered the right sequence? If you're seeing the list of channels with versions numbers then you went L-R-L-R-L instead of R-L-R-L-R.
Roku Community Streaming Expert
Help others find this answer and click "Accept as Solution."
If you appreciate my answer, maybe give me a Kudo.
I am not a Roku employee.