attempt to delete row 2 from section 0 which only contains 1 rows before the update

[gerchicov-bp]

Initial state:
3 sections, the first one contains one row, other contain 2 rows

Destination state:
all the sections except of the first one are removed

Error:
attempt to delete row 2 from section 0 which only contains 1 rows before the update

Additionally: how diff(old:new:) works if it tries to delete and reinsert the first section - extra action?!