Is it a theme issue since on https://dmaster.demo.civicrm.org the primary email has the label in bold. css/contactSummary.css has this: https://github.com/civicrm/civicrm-core/blob/049f56c55afb4cf7ff969a626bce7887f9dbe5e1/css/contactSummary.css#L3-L5
.crm-container .primary .crm-label {
font-weight: bold;
}
Can you see what the label has for css on your end?
OK, I think I found something interesting.
The css for the phone field has:
class="crm-summary-row primary"
But the css for the email field seems to get translated:
class="crm-summary-row primair"
'primair' is dutch for primary.
I think in civicrm-core/templates/CRM/Contact/Page/Inline/Email.tpl
<div class="crm-summary-row {if !empty($item.is_primary)}{ts}primary{/ts}{/if}">
should be
<div class="crm-summary-row {if !empty($item.is_primary)}primary{/if}">
I will try to come up with a pr
(PS. I wonder if there are other places where a translated string ends up in the css)
added git:civicrm-core sig:bug sig:usability triaged labels
PR: https://github.com/civicrm/civicrm-core/pull/23686
To answer the afterthought about whether there are more, this looks like the only one, at least in that format: grep -r -P 'class="([^"]*){ts}([^"]*)"' templates
closed