Baby late evening wakefulness

[Trundle13]

Wondering whether anyone can shed any light on this!

Since he was about 5/5.5 months, DS (6.5 months) has been waking up after his two-hour evening cluster feed (8-10pm) and is wide awake and ready to play again. (I feed him to sleep in our bedroom with low light and no TV/other noise - if we have to talk, DH and I whisper - this is how it has been since he was born.)

We keep the room dark and quiet and try not to engage him during this time, but it regularly takes an hour to calm him down enough to feed back to sleep. This has been happening more and more frequently, to the point it's now every evening.

He usually has three naps during the day, the third nap finishing between 3pm and 6pm - generally between 4pm and 5pm. Total nap time during the day 2.5 to 4 hours. Bedtime routine starts around 7:30pm. He is usually asleep within ten minutes of starting to feed, but then suckles in his sleep for another couple of hours as described above - cannot be moved during this time or will wake up crossly!

Night sleep has been disturbed recently due to teething; he'll generally wake up an hour or two after put-down (midnight/1am - this also started around 5 months!), then feed back to sleep, waking for the day between 7am and 8am with perhaps one more waking.

Is this late evening playfulness just another phase? Anyone got any tips/experience?