Span element gets stripped from editing

We have added button on RTE toolbar so that we can put selected text inside <span>

Now, that functionality worked perfectly fine in our previously installed version (0.14.21) but now we updated to 0.14.43 and when I select the text and want to put it in <span> it does it in code, but RTE doesn't make it as element until I reload my template. It acts like part of all text instead of being selectable span block.

Generated code:

<div id="i3x1e" style="padding: 10px;">Insert your 
  <a href="" id="ib14x" class="link">text</a> 
  <span id="itjbi" class="span0">here</span>
</div>

Span button code:

rte.add('span', {
    icon: 'Span',
    result: rte => rte.insertHTML(`<span>${rte.selection()}</span>`)
});