I have two laptops - both running Linux Mint 18.2, Xfce 64bit, both with LibreOffice 184.108.40.206 Unless I am completely missing something I have set the LO Tools>Options the same for both computers.
When I set them both up I noticed that in Calc documents with buttons (push buttons or options buttons) the underlined accelerators were not visible. (But they did actually work - I noticed that because I had predetermined the accelerator with the tilde~). This was the same for both laptops
Later I must have altered some setting somewhere (in LO or Linux I know not which!) because now one of my computers shows the accelerators perfectly well but the other doesn’t.
Can anybody tell me where the setting is?