Crackling Lance of Disintegration Shock Effect Bug

Crackling Lance of Disintegration has an innate +20% maximum shock effect according to its tooltip, but in game you're still limited to a 50% shock.

It's not an issue of dealing enough damage either, if I allocate the Lightning Mastery for +15% max shock, I reach 65%. If I unspec it I'm back to 50%.

Edit: Figured the issue out. I'm using Berek's Respite which spreads shocks, but this does not inherit the added max shock from Crackling Lance. So while your initial target would get shocked for 70%, it only spreads a 50% shock.

So the base 50% with 20% from gem and the mastery 15% is it possible to bring it 85% shock effect on ennemy?