Minecraft has a default spawn protection of 16. Which you are able to change easily.
You are able to completely disable it or make it larger/smaller if you wish.
Changing The Protection Size
To change the spawn protection radius, you will want to click on the files drop down tab, then select config files.
Once on the config files page, you will want to click on the Server Settings option, the first one to the top.
Find the option titled Protected Spawn Size.
In the text box, you are able to change the numerical value. For example, if you want a bigger protection size, you can set it to 20 or some higher number.
Though if you want a lower protection, then change it to a number lower than 16. For example, 14 or a lower number.
Disabling Spawn Protection
To disable spawn protection, you will want to set the value to 0.
Saving The Changes
After you inputted the value you want, scroll down to the bottom of the page, and click the big blue save button.
Once saved, head back to the main page of your control panel, then restart your server.
Updated on: 11 / 18 / 2020