I planted a rose tree last year and it had several buds but they did not open into flowers. The same thing is happening this year. It is a hybrid - no flowers, just buds.
That can be extremely frustrating I know. Here is a link to an article I wrote on this subject. Please give the article a read and let me know if you have further questions or need more help. If it turns out to be an insect issue, get some Bayer Tree and Shrub granules. Give the tree rose some of that per the label instructions and you should see some nice blooms. Article Link: https://www.gardeningknowhow.com/ornamental/flowers/roses/no-blooms-on-roses.htm