Sleep cycle changes are common during growth spruts.Maintain consistent bed routine.Ensure he is fed well and nappy is not wet.

Greetings,sudden shift to short naps (20-30 minutes) and frequent night waking could be due to a developmental leap, a growth spurt, or a new discomfort like teething or a minor illness. To help, try a consistent bedtime routine, ensure the room is dark and cool, and soothe him back to sleep gently when he wakes. If the pattern persists or he shows other signs of illness, it's best to consult  pediatrician in person