I use MeanWell power supplies. Never had one fail. Also, buy a bigger wattage unit for extra margin. Usually can pick one up reasonably on eBay.

https://www.ebay.com/itm/124547366466?hash=item1cff99fe42:g:9LwAAOSwQV1fZ8e0&amdata=enc%3AAQAIAAAA8NLcgYmOdy4WSY5aeFlWfOiVMxtAgyWYEQunSwwaIYXrCmu6rP1Snd%2B2MPEhLGlmJ83hSgOHqMejBSGTHcjAvDO61Yh5dewO3HKowWr4NiWjAoHItFXyX7CNg4EJMoslAIfenJ3RteuLdIjP4g7SVZq6N5auIF8G0bvqkoyBQJBPPq6SEemzVjM%2F26aR8HGHI4N5sSbSFcNHiRyquWqovxHwj2jf5IGY2G8nma29Pitpo11ofJ%2FPprlxuRShzc%2BLUJoBox1T3GAOMEOQTTiTiMfcs73441Va14BrcCkndh2Q1OqPnwYKUyUE0JvYq6cMTw%3D%3D%7Ctkp%3ABFBMptvjzYhj

Is the "transformer" a real, magnetic transformer, or an electronic one? I use only magnetic ones, for one thing, electronic ones tend to add noise to the house wiring.

You have less than 60 watts on a 100 watt transformer - should be plenty of margin.

You might check to see if it's pulling more amps than you think ( because of defective wiring or something).

You might consider redoing the lights and changing to LED since you are replacing the power supply anyway. Lower power requirements and less heat.