I can share the general Jain principle, but for the exact practice you asked (pachkkan after ekhasna), check a trusted Jain authority.

• Ekhasna means taking only one meal during a day, usually during a period of austerity or a vrata.
• In that context, the common practice is not to eat again after completing that single meal for that day; the next eating would be the following day (or as prescribed by your vrata) rather than continuing with multiple meals.
• Pachkan (the specific practice you mentioned) is not universally described in the same way across all Jain traditions, and exact rules can vary between Digambar and Shwetambar lineages or by local guru guidance.

If you want a precise ruling, I can look up authentic Jain sources for you.