Why is this an issue?

Placing an if statement on the same line as the closing } from a preceding if, else, or elseif block can lead to confusion and potential errors. It may indicate a missing else statement or create ambiguity for maintainers who might fail to understand that the two statements are unconnected.

The following code snippet 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 elseif instead:

if ($condition1) {
  // ...
} elseif ($condition2) {
  //...
}