Wotcha and welcome,
Not got a scoob diesel myself however on my diesel van issues with glow plugs were traced to the supporting relay, so the issue may not be the plugs themselves. Dependent on mileage it may be time to replace them anyway??
The jumper instead of a fuse is not great - indicates an earth somewhere which def needs investigating as an earth can turn your wires into smoke generators - this is not fun and makes a funny smell