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

Off the top of my ancient head:

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

General Introduction to Boundaries from Panahi Counseling:

What measures do celebrities take to protect their images from being used for commercial purposes without permission? How much does this typically cost them?

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

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

Obsessing about clients outside of work hours.

Cardinals Place Jordan Walker On 10-Day IL, Select Ryan Vilade - MLB Trade Rumors

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

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

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

UFC 316 results: Kayla Harrison finishes Julianna Peña, squares off with Amanda Nunes - MMA Junkie

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.

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

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

Why do people hate on Serena (anime character)? What did she ever do to anyone except be a good friend to Ash Ketchum and an awesome trainer herself?

Serious disappointment when the client cancels a session.