I don't know how to give you a copy of my world so here is a link to OneDrive to download it. Keep in mind that I can't replicate the issue in a single-player session. We are using the Bedrock server EXE from the official Minecraft website.
I'm running a server to play with my friends, and we all have the same exact issue since the update to 1.18. There is no spike when lag occurs. It's just constant lag whatever we do.
@GoldenHelmet the more courageous people who still playing on my server with all those lags are saying to me that they're experiencing lag when more than 3 players are in the game. I am willing to give you the address of the server and the correct port number but more in a private message. Otherwise, I will link a OneDrive link to the complete server files. We have several locations of activities. Maybe if you put a player at each position then you can replicate the bug. The main village is around 791, 67, 18 and here are all other populated areas. 943, 68, -93 , 1013, 63, 163 , 1537, 64, 386 , 534, 63, 410. Almost all bugs mentioned before by other people here have occurred in our world. If you need any more information then please ask me. I want this issue solved for everyone as the game is not playable at this point. All these lags started as soon as I updated to 1.18.
Link to download the whole server through OneDrive