Looks like someone just filed this as a Chromium (v77) bug. See issue tracking it here.
Update 1: As noted in the issue tracker and comments below, this should now be fixed in the latest stable release, which is being rolled out now (2019/10/11).
Update 2: Despite the bug being marked as fixed/closed in monorail, canary (80.0.3977.4) still appears to have this behavior. As others have noted there is a global limit of 255. However, the fact that connections opened by JS don’t get closed/reset when the page is refreshed still seems like a bug to me.
