Should/can a monarch be political?


I’m currently watching the BBC doc on Prince Charles for his 70th birthday. For those of you who don’t know, Prince Charles is very politically active, especially concerning the environment. However, since restrictions on the crown in the 17th century, the influence of the power of the crown is almost next to none. They are unable to delay or influence parliament. Queen Elizabeth II is known for just how politically neutral she is, she is very private about her beliefs. Prince Charles has recently stated that he, upon succession of the Crown, will stop speaking out on political areas as much as he does now. Examples of what the Prince of Wales has been involved in: the Prince’s Trust (military), campaigning for environmental change, visiting countries after natural disasters, and he and the rest of the royals visited (and spent more time at) Grenfell after that horrific fire

So, my question. Do you think it’s acceptable for a sitting monarch to speak out on political issues? Or should they be politically neutral? Is there a limit to what they should be able to speak out on/about?