"Must Be Blocked If Able" incorrectly interacts with evasion

**Describe the bug**
Rules regarding blockers not properly enforced.

**To Reproduce**
Control a menace creature and a vanilla creature.
Opponent controls two vanilla creatures.
Cast Enlarge targeting your menace creature.
Attack with both.
(Depending on what the opponent chooses to do)
Observe that the computer is allowed to decline to block the menace creature, even though they are able.

**Expected behavior**
The opponent should be required to double block the menace creature as per 509.1c.

**Screenshots**

**Desktop (please complete the following information):**
- OS: Windows 10
- Forge Version 2.0.05

**Additional context**
Add any other context about the problem here.