RRule datetime generation randomly wrong

import { z } from "zod";
import { calendar_v3, google } from "googleapis";
import { DateTime } from "luxon";

//...

const rrule = RRule.fromString(event.recurrence[0].split(":")[1]!);
if (!event.start?.dateTime) return null;

const startDateTime = DateTime.fromISO(event.start.dateTime).setZone(
  "UTC",
);

rrule.options.dtstart = startDateTime.toJSDate();
rrule.options.tzid = "UTC";
const utcStartTime = startDateTime.toJSDate();

rrule.options.bysecond = [utcStartTime.getUTCSeconds()]; // Never mentioned in the docs, works for some reason
rrule.options.byminute = [utcStartTime.getUTCMinutes()];
rrule.options.byhour = [utcStartTime.getUTCHours()];

const dates = rrule.all((d, i) => {
  return i < 20;
});

console.log(dates.map((d) => d.toLocaleString("en-US"))); // log 1

const meetingModifications: calendar_v3.Schema$Event[] = [];
for (const date of dates) {
  const eventModificationId = `${meetingLinkCheck.googleCalendarEventId}_${DateTime.fromJSDate(
    date,
  )
    .setZone("UTC")
    .toISO()
    ?.replaceAll("-", "")
    .replaceAll(":", "")
    .replaceAll(".", "")
    .replace("000Z", "Z")}`;
  try {
    const eventModification = (
      await calendar.events.get({
        calendarId: "primary",
        eventId: eventModificationId,
      })
    ).data;
    if (!eventModification) continue;
    meetingModifications.push(eventModification);
  } catch (error) {
    console.log(eventModificationId, date.toLocaleString("en-US")); // log 2
    continue;
  }
}

meetingModifications.sort((a, b) => {
  const dateTimeA = a.start?.dateTime ?? "";
  const dateTimeB = b.start?.dateTime ?? "";
  return dateTimeA.localeCompare(dateTimeB);
});