That's packet type 10017 which deals with client updates.
The structure of the packet is generally a list of updates based on subtypes.
The first one you posted is a single update of type 25 and the second packet is a dual update (just the way some updates are handled by the client) which is of type 27.
There's no need to sniff packets though when we've already told you it's a statuseffect flag. Those are all listed in the client conveniently and you can test them all within a few minutes by using a simple command to send update packets to your client (proxy or pserver, it's all the same. Just gotta send the packet to the client)
Just shift 1 bit at a time till you find it. It's almost guarenteed to be in the second effects pool as it's a new flag. Alternatively just look in the client stateff list and it will list which bit offset controls it.