Telegram bot api: sendPhoto do not render html

Question

I'm composing messages in this way

const reply_telegram = {
        "chat_id"               : MIRKO,
        "photo"                 : row.image_url,
        "caption"               : '<b>Wow</b>',
        "parse_mode"            : "HTML",
        "disable_notification"  : true,
}

For the goal of this question, focalize on

"parse_mode" : "HTML"

I am usng the sendPhoto instead of classic sendMessage.

1. Official docs state that I can use a caption and parse_mode in the sendPhoto method
2. I am actively using sendMessage with html content, and it's handled as HTML as I want

In short, the problem is that: message is sent, photo is delivered, caption text is printed under the photo, tags are not printed, but the title is not bold as I requested.

What am I missing?

Answer 1

Actually, July of 2019, seems that the problem is no more present. Probably Twitter has fixed it.