"Notes 1. The tonnes, grade and recovery of ore processed do not...

"
Notes
1. The tonnes, grade and recovery of ore processed do not reconcile with silver produced due to the build-up of in-circuit stocks.
These stocks include;
- approximately 41,000 tonnes of oversize material at 91g/t silver and
- 36,000 oz of silver produced in December which was not smelted and was contained in concentrate
"

So the actual silver produced came from only 177k - 41k = 136k tonnes of ore.

There are 36k oz in circuit, so assuming it is all from this qtr 277k + 36k = 313k oz

313k oz / 136 k tonnes = 2.3 troy oz per tonne = 71.5g/t on average. As you say, bad grades in Oct/Nov have something to do with it