You might have to order overseas.
I assume you have QR 10x135mm + 6 bolt, so I have two suggestions:
Mavic Crossride FTS-X 27.5 Inches Rear Wheel - 6 Bolt - QR
Shimano WH-MT500 27.5"
Mavic Parts ▶ Useful replacement wheel - simple and reliable. W. aluminium rim & proven FTS-X freehub.
www.bike24.com
Buy WH-MT500 27.5" Rear Wheel at BEST PRICE ✓ Order Shimano Wheel 27.5" Rear Wheel at Bike-Discount now! ➤ Shimano Online Shop
www.bike-discount.de
Both those wheels can accommodate 2.4" tires and are on the cheaper side at under 100 euros. They have 24 spokes, but I personally wouldn't focus on that too much. It's already hard enough to find the proper wheel!
Beware that the Shimano wheel uses centre lock, so you will need to purchase an adaptor like this if you currently have 6 bolt:
Buy Centerlock Adapter SM-RTAD05 at BEST PRICE ✓ Order Shimano Disc Adaptor at Bike-Discount now! ➤ Shimano Online Shop
www.bike-discount.de
But even if you purchase the Center Lock to 6 bolt adaptor, you will still need a special centre lock tool.
Another gotcha: Haibike sometimes calls their wheels QR5x135 in their documentation. This is actually the same thing as QR 10x135. The explanation:
5x135 mm refers to the 5mm clincher rod that goes inside the axle.
10x135mm refers to the 10mm axle that houses the clincher and fits into the QR frame dropouts.
It's hard work looking for a wheel, but hopefully this will have helped.