The easiest way is to replace the MCP23017… hopefully you havn’t killed the pin on the Raspi… Can you try to run i2cdetect again? If the MCP2301 is killed you should not see any device in 0x20 reported.
If you see a device, the Raspi pin maybe killed. You can try to use another free pin (perhaps 37?) and change zyncoder data for INT_A.
Regards, Holger