Mine Alert is a top notch plugin that'll notify you if someone is actually using X-Ray.
Mine Alert notifies staff members with notifications on how much a player mined of a certain ore / spawner. Violation amounts are totally configurable. Say for example if a player mined diamond ore 3 times or what ever the configuration has it set to it'll notify the staff member with notifications on of what they mined, and how much they mined it. All X-Ray data does save cached data then resets after a certain interval has passed (also configurable). Mine Alert flags players that mine all ores that have been introduced in Minecraft between 1.13-1.18, and even default overworld spawners along with Blaze & Magmacube spawners.
This plugins offers a lot of options when it comes to trying to catch X-Rayers. Features including:
Toggle on and off alerts
Full MySQL Support (optional)
Inspect menu of how much a player mined.
Settings menu for your staff to catch those who use X-ray easier. Settings such as toggling picking up items on and off, turn on night vision / turning off night vision, and switch in between survival and spectator mode.
Interval command to see how long until all X-Ray Data saves then resets (configurable)
Easy resource for your staff to catch X-Rayers easier.
And more to come.
/minealert notify(turn on and off alerts)
/minealert interval (see how much time is left before date caches and resets)
/minealert inspect <player> (menu display of player's mine data)
/minealert settings (settings menu to make it easier to catch xrayers)
/minealert reload (reloads all files)
minealert.help (to access the help page when /minealert is typed)
minealert.notify(access notify command, interval command, & to receive notifications from the mined block if surpasses the flag amount (configurable)
minealert.admin (reload all configs command)
minealert.inspect (to access the inspect command to inspect players)