Why is this an issue?

When an if is placed on the same line as the closing } from a preceding if, else or else if part, it is either an error - else is missing - or the invitation to a future error as maintainers fail to understand that the two statements are unconnected.

This code is confusing

if (condition1) {
  // ...
} if (condition2) {  // Noncompliant
  //...
}

Either the two conditions are unrelated and they should be visually separated

if (condition1) {
  // ...
}

if (condition2) {
  //...
}

Or they were supposed to be exclusive and you should use else if instead

if (condition1) {
  // ...
} else if (condition2) {
  //...
}