When You use Tools and Modifier…They use the scale of Your object to get the result…Default scale is 1
You can see it in N -Panel - Transform - scale…If You Scale or rotate a object in object Mode…It will change the objects Scale.
Tools and Modifier will not work right…You can reset scale…Object selected…Hold Ctrl - a …Seletc apply rotetion & Scale
It will set scale to 1…Now it should work…
When You use tools…Look in the Menuline…There are info how to use the tools.