Dota 2 Wiki
Known Bugs

Frost Blast[]

Frost Blast uses the wrong AoE targeting cursor when selecting the spell while the cursor is on a valid target
Single targeted spells with an AoE effect have a special AoE indicator. This special indicator does not show up when the spell gets selected while the cursor is pointing on a valid target for the spell. Instead, the default AoE targeting cursor appears.
Following abilities are affected by this bug:
26 February 2017

Frost Blast's particles and audio are applied before spellblock check, instead of after
When the Frost Blast target has Spell Block, the spell still creates the particle effects and plays its sound on the target. Similarly, when Frost Blast gets reflected back to a spell immune unit, the particles/sound appear on the spell immune unit.

Test of Faith has this issue as well.
20 December 2017