Odd Conn busy error with Pool.Acquire and Begin

I have found a workaround to my problem but I think this may point to a deeper bug. The code below works most of the time, but under odd conditions that I noticed "Conn closed" errors. The second code block, while functionally identical for my purposes has not yet manifested the "Conn closed" error.

...
var pool *pgxpool.Pool
...
conn, err := pool.Acquire(ctx)
// error returns oddly here
if err != nil {
  return err
}
//code never reaches here on error
defer conn.Release()
tx, err = conn.Begin(ctx)

Second code block:

...
var pool *pgxpool.Pool
...
tx, err = pool.Begin(ctx)
// pool.Begin successfully establishes a connection and initializes a transaction.
// No "Conn closed" error observed as of yet. 

Apparently, starting the transaction directly from the pool avoids this issue. Is there any insight as to why this might be the case?

Start with the Acquire-then-Begin and pool.Begin call sequences shown in the issue, and compare how each handles the connection. Reproduce the intermittent "Conn closed" error under the reported odd conditions; done means identifying the cause and determining the appropriate behavior or fix.