How to:

1. open a page on VE
2. select a piece of text that includes a reference
3. click and hold this sentence to move it somewhere else in the text

Expectation:

• text and reference are moved

Results

• text is not moved
• this has consequences: any other move with no ref tag would work but with the following issues that may appear:
  • on a big article (Modélisme ferroviaire on fr.wp, 189111 octets), any other text without a reference moved after this first move will be randomly cut
  • you can't save the page

Example concerning the odd consequences
I was editing https://fr.wikipedia.org/w/index.php?title=Accord%C3%A9on&veaction=edit&safemode=1, making improvements on the following sentence:

Et que la construction de sa machine est exclusivement née de l'étude anatomique du Larynx[4].

I've done the following:

1. select the entire sentence to move it: no move
2. changed "Larynx" for "larynx": the save button doesn't turn blue
3. added a link to "larynx": link is created, the save button doesn't turn blue

Browsers and configuration
Happen to me using Firefox 69 using safemode or not.

I've also spotted a similar feedback on no.wp (that includes an issue with copy/pasting too), using Firefox and Edge, both in safemode or not.

May be related to T168901: Can't drag-and-drop text to rearrange (cut and paste) in Safari.