When you've done as much wrong as Biggs it's difficult to know exactly why someone is mad at you. But in this case it's most likely because he or his minions stole the active component of her hammer, being a key part of inn's defences.
Question is, has the Spear been melted down yet?
When we last saw the spear (https://www.missmab.com/Comics/Vol_1965.php)
I wonder if Biggs knows about Jyrras having the spearhead. And if so, will his belief boon keep him from folding under the force of Alexsi's wrath?