Error 0x2D is due to SD card issues. It has nothing to do with wired Ethernet. Yes, try to change the microSD card — it’s located close to the top edge of the circuit board. Any size is fine, probably 4GB and 8GB is the most common, you almost can’t find anything smaller, and larger is more expensive.
Also, I would highly recommend you to upgrade your firmware to 2.2.1(0). Your current firmware 2.1.9 is outdated and has known issues with the current UI/app. Upgrading to the latest firmware will solve this problem.
https://openthings.freshdesk.com/support/solutions/articles/5000381694