I’ve found some templates are messing with the default blockquote settings. I used this bit of css to change it to what I need.
.wp-block-quote {border-left-color:#13aff0 !important;border-left-width: 8px !important;}
.wp-block-quote p {
margin: 30px 0 20px;
}
.wp-block-quote {font-size:110%;font-weight:bold;}