iframe height too narrow, doesn't respond to height attribute

[robofunc]

I have an iframe pulling in a calendly and for some reason it's not tall enough to show the content:

I did a test using the same thing on a different site and I'm able to make the iframe taller by making the height attribute greater than 100.

I can't figure out why it would work on one site, but not another. Both sites are running Hello Elementor theme and both are using Elementor 3.7.8 and Elementor Pro 3.7.7

[robofunc]

I was able to get it to work by using object and embed. Still not sure why iframe was behaving inconsistently, though. ¯_(ツ)_/¯