Messages not displaying full text message in window, but rather a tiny font in popup window on Mac Studio Display

Messages on my Mac Studio with Studio Display - seem to be hiding my longer messages. I see the first 5 sentences of a text message, but then the rest is hidden. there is a right pointing caret at the bottom right of the message that will produce a popup of the entire text, but in tiny font 9 pt font. i prefer to read my text messages on my large Studio monitor but this defeats this as the tiny popup font is hard to read. my workaround is to copy the text & paste it into a notepad so it will appear in a nice legible 15 point font.

is there a way to force Messages on my Mac to display the entire text message in the text bubble at the preferred 15 pt font size rather than displaying it as a popup in a tiny font?

all the solutions i've been getting are for messages not showing or syncing issues with an iPhone. this is not my question. on my Mac Studio home computer - i just want Messages to display the full text messages in the display font, not as a popup.