Adaptive Card Conversation Limit Issue in Teams via Bot Framework Connector

We are sending an adaptive card containing text blocks, column sets, and action sets via the bot framework. We are sending the adaptive card to the Teams channel. Below is an example of such an adaptive card.

In some cases, we wanted to send up to 50 conversations, adding them as a column set in the adaptive card, and sending it to the Teams channel using the bot framework connector client.

Also, we restrict the conversation count to 20900 in the code, we can still add over 30 conversations to the adaptive card, but Teams only displays 15 to 20 conversations once its send to the teams' channel.

Is there a character limit for sending adaptive cards via the bot connector client?