Short answer: In the Digambar tradition, many ascetics avoid dairy products, including paneer. While some Svetambara practices may permit dairy in limited ways, Digambar monks are generally strict about avoiding milk and its derivatives.

Why this is so (in brief):

• There are well-known Digambar examples where monks chose not to consume milk at all. This aligns with their emphasis on minimizing harm and following strict ahimsa in daily meals. ( jainknowledge.com)
• While Jain lay followers and some Śvetāmbara practices may include dairy in a more flexible way, the ascetic rules for many Digambar renunciates typically exclude milk and dairy products like paneer. ( jainknowledge.com)

Note:

• Practices can vary by guru, sangh, and region. Always follow the guidance of your guru or local sangh.
• Paneer is a dairy product, and most strict Digambar ascetics refrain from dairy as part of their vows.

You can read more about milk and dairy considerations in Jainism here and about Jain foods lists here .