@supports rule raises inspection error in LessCSS

Using nested `@supports` rules creates an inspection error even though it's valid LessCSS. 

.some_selector {
  margin-top: 20px;

  @supports (position: sticky) {
    margin-top: 6px;
  }
}

This is correct Less code: http://lesscss.org/#nesting-nested-at-rules-and-bubbling
It also compiles correctly without warning, but raises an inspection error in PhpStorm 2019.1. 

Note: this is not the same as this other issue, since it's in Less and not CSS / SCSS. In the other issue there hasn't been any response since October, I guess because this syntax is not valid in CSS (it definitely is in Less though). 
https://intellij-support.jetbrains.com/hc/en-us/community/posts/360001224660-Error-on-css-inspection-using-support-bootstrapv4-