What are some signs that a therapist may have poor boundaries with their clients?

Serious disappointment when the client cancels a session.

Frequent phoning or texting of clients to “check up on them and make sure they’re OK.”

Struggling with fantasies of deeper connections with clients, whether sexual or parental or other intense or intimate relationships beyond psychotherapy.

Rubin Observatory’s Stunning Result Proves It’s a 'Game Changer' for Spotting Dangerous Asteroids - Gizmodo

Disclosing feelings, fantasies, and experiences to the client in ways not related to the work the client is engaged in.

Eager anticipation (or anxious anticipation) of the next session in ways that distract.

Off the top of my ancient head:

Yvette Cooper yet to agree deal three days before spending review - BBC

Failing to mention the client in supervision/consultation, out of fear the supervisor/consultant will advise return to ordinary healthy boundaries.

Obsessing about clients outside of work hours.

Sense of competition with persons who are important in the client’s life.

Artists get better with age, e.g., painting. Yet when it comes to pop music, the famous work tends to be written when musicians are in their twenties. So, why aren't Bob Dylan or the Stones banging out amazing tunes now?

General Introduction to Boundaries from Panahi Counseling:

These items can happen fleetingly, briefly, in any therapy, but if they’re frequent, it’s definitely time for the therapist to get some good, solid supervision/consultation.

Session-expressed curiosities about client details not relevant to the therapy.

What are the withdrawal symptoms of Klonopin 1mg?

Routinely going over the time limit with certain patients, compromising the time for the next client.