One key piece of information in troubleshooting that snag is that the engine hangs up around 35%.
The Arriel and Arrius engines are similar in design.
When you shut the engine down, at around 40% Ng, the pressurizing valve opens and redirects the fuel in the engine back to the fuel tank, rather than continue into the engine.
When you start the engine, fuel pressure is supposed to close the pressurizing valve and start fueling through the sling wheel, rather than the start injectors.
If the pressurizing valve doesn't close, the start will stagnate around 35% Ng.
Also, you indicate the aircraft was built in 2001.
I believe the fuel system components are supposed to be overhauled every 10 years. Don't quote me on this particular component, I don't have the manuals in front of me, but certainly worth checking.