Perhaps they are better trained. Six of them were killed recently when Al Shabaab targeted their base. From the video, the attackers got too close for a secure military base. The silhouette of an APC that is supposed to guard the entrance can be seen very clearly in the dark Kenyan night. I would say once an attacker has reached that point, your outer defense is totally put out of action and it remains for everyone inside to act.
If it were not for obvious mistakes by the attackers (which one can see in the video) the attack would have been devastating for KDF. For instance, they crowded together and this became easy targets for a trained sniper with night vision. Alternatively, a single artillary round fired directly at their position would make short business of the gang.
Note however that all the Kenyan forces get the best training. The only problem is that they never get to use the high tech equipment they saw in college. Some never fire a gun for years and have to do it for the first time during an attack. That is because money meant to buy bullets for test firing and target practice is for the chiefs to eat. They "buy" the bullets alright and then recover the cash used by selling the same onwards.
I think this new spike in attacks means ISIS has extended its reach. Al AShabaab alone can't overrun a military base of trained troops.
I think those Burundians are poorly trained soldiers. A glorified militia.
I respect KDF training. But they are let down by their top brass and DOD who siphon off loads of money. Leaves them with limited, dilapidated, outdated equipment.
So you have vast swathes of territory that they can't cover even inside Kenya as the Lamu attack proves.
Being Kenyan, they are also not above the corruption bug in the same way that the ocean is not above the clouds. Unfortunately.