Title: Companion cannot be cast despite deck meeting all Companion requirements

Description:

I have encountered a bug involving the Companion mechanic in MTG Arena.

My deck fully satisfies all the Companion requirements, and the game allows me to select the card as my Companion before the match starts. However, once the game begins, I am unable to cast or use my Companion as expected.

Steps to reproduce:

1. Build a deck that meets all Companion requirements.
2. Select the Companion.
3. Start a match.
4. During the game, attempt to use the Companion.

Expected result:
I should be able to pay {3} to put the Companion into my hand and then cast it normally according to the current Companion rules.

Actual result:
The Companion cannot be cast or used, even though the deck meets all the required conditions.

Platform:
Android

This appears to be a rules or gameplay bug related to the Companion mechanic.