Problem with MH lamp and Ballast?

Hello im having a problem that i hope some of the experienced growers can help me with.
Im using the GIB lightning 400W mh lamp and my ballast is Maxibright digilight pro 400W its a digitalballast.

When my timer goes on for the light to start sometimes it take up to 30 minuts for the lamp to start sometimes it dosent start at all and my ballast shows its a lamp failure and i have to restart it again many times with the same result. If i put my hps light in it of the same brand and watt it starts of right away like it should do. Im suspecting its my ballast that is not compatible with mh lamps at al ? Please help me im confused / Flodas

Ballast http://www.hydrodaze.co.uk/PBProduct.asp?ItmID=12029197

Bulb https://www.maxgrowshop.com/sv/lamps-mh-grow/44-mh-400w-gib-growth-spectre.html

I'd start out the cheapest and most practical way......Get a new MH bulb and try it.

Maxibright 400 Watt Digilight Pro Digital Variable Output Ballast

The Maxibright 400 Watt Digilight Pro Digital Variable Output Ballast is a high quality, reliable ballast. Utilising Digital technology, it will deliver more lumens for less electricity than standard ballasts while running cooler and quieter too! With 4 power output settings you will be able to dim your 400 Watt lamp as well as boost the light output as it gets older via the Super Lumen function.
Maxibright – great value lighting products
High internal components for reliability and long-life
Strong, heat-finned case
Compatible with HPS lamps
Compatible with MH lamps (only at their rated wattage. MH lamps must never be dimmed or used on the Super Lumen setting)
Effectively silent in use
RF shielded
Features soft-start technology for low start-up current
Output will not degrade with age like standard ballasts
Super Lumen switch allows you to get more life out of aging HPS lamps
Has 4 settings for 400 Watt HPS lamps: 250w, 275w, 400w, Super Lumen (440w)
Has 2 settings which can be use with 250 Watt HPS lamps: 250w, 275w
Includes it's own fault diagnosis circuitry to tell you what's wrong in the event of a problem

PLEASE NOTE: Maxibright recommend this ballast for use with HPS and MH lamps. However, MH lamps should ONLY be run on the normal setting (i.e. 400W for a 400 watt lamp and 250W for a 250 watt lamp). MH lamps should NEVER be boosted or dimmed by running them on a different power setting than the rated wattage printed on the lamp.

its still one of the most expensive HID light I've seen in a long time..?
get your ballast checked or return to replace

good luck