Reservation - Repeat - Custom empty

[manoficons]

Describe the bug**

When trying to make a new reservation with option ->Repeat -> Custom
clicking in the "Repeat On" field opens a small scroll bar without content.

To Reproduce**

Steps to reproduce the behavior:
Got to new reservation -> Repeat -> Custom -> Repeat On field

Expected behavior**

Dropdown menu should show content/calendar?

LibreBooking version develop - docker.

[belcirelk]

I don't have this problem in the non docker devlop version. I am able to select dates. That's the only place you see problem with the date picker?

[manoficons]

When I was looking further I also could find it in

Find A Time -> Repeat -> Custom -> Repeat On

Editing Reservation -> Repeat -> Custom -> Repeat On

So I think it's everywhere where this kind of date Picker is used.

[JohnVillalovos]

I spun up a Docker container and I could not reproduce this issue.

[JohnVillalovos]

Someone else pointed out that it looks like Javascript issues. Any chance you have Javascript turned off in your browser?

[manoficons]

Reproduced the issue on Firefox 149 (js on), with Opera 128 and Safari.
Unlikely that it is a browser thing.

Maybe my docker behaves different because it is running on synology?
Set up with yaml and Contanier Manager on DSM 7.3.

[belcirelk]

nothing in the browser console that can help? Have you try to change the settings for local libs in the config.php (not sure if it makes sense for docker)?

You can also try the demo website on the same device to see if it works, it will tell you if it's your install or device.

[manoficons]

The demo works as exprected. So no browser problem, it must be my install.

I already changed the local libs setting in config file without any effect.

Strange it's only the "Repeat On" fields not working.

[JohnVillalovos]

Analysis performed by AI

Thanks for the detailed report and follow-up screenshots.

My leading theory is that this is a Flatpickr date picker initializing while its container is hidden. The RepeatDate input lives inside #customDatesDiv, which starts with the Bootstrap d-none class. The initialization code in DatePickerSetup.tpl already handles deferred initialization for modals and collapse elements (waiting until they're shown), but there's no equivalent deferred path for the custom-repeat section. So Flatpickr may be initializing against a zero-dimension hidden container, which can produce exactly the empty scrollbar you're seeing.

This would explain:

• Why only the "Repeat On" field is broken (other date pickers are visible at init time or inside modals/collapses with deferred init)
• Why it's environment-specific (different platforms handle hidden-element rendering differently)
• Why the demo works fine (subtle timing or CSS differences can mask it)

A secondary possibility is that Flatpickr assets (CSS/JS) aren't reaching the browser. Running on Synology DSM 7.3 with Container Manager, it's common to have a reverse proxy in front of the container (Synology's built-in reverse proxy, Nginx Proxy Manager, etc.). These can sometimes strip, block, or incorrectly cache static assets like CSS and JS files. A use.local.libs config mismatch or the NAS network blocking CDN access could also cause this.

To help narrow it down, could you check a few things in your browser's Developer Tools (F12)?

1. Network tab: Reload the page, filter for flatpickr. Do flatpickr.min.js and flatpickr.min.css both load successfully (200 OK), or is one missing/404?
2. Console tab: Are there any errors when you click the Repeat On field?
3. Inspect the element: Right-click the empty scrollbar → Inspect. Is there a .flatpickr-calendar element in the DOM? If yes, does it have content but zero/very small height?
4. Other date fields: Do the normal visible date fields on the same page (like reservation start/end date) work correctly?
5. Reverse proxy / Docker setup: Are you using a reverse proxy in front of the container? What does your Docker Compose / Container Manager configuration look like for port mapping and volumes?
6. Config: What is your use.local.libs value in config.php?

Questions 1 and 3 will tell us the most. If assets load fine but the calendar element exists with zero height, that confirms the hidden-init theory. If assets are failing to load, it points to the Synology/proxy/config setup, and we can troubleshoot from there.

[manoficons]

1. Network, flatpickr.min.js -> Status 200 OK.
2. Console: no errors.
3. <div class="flatpickr-calendar hasWeeks animate static arrowTop arrowLeft open" tabindex="-1" style="width: 1px;"><div class="flatpickr-months"><span class="flatpickr-prev-month"><svg version="1.1"
<div class="flatpickr-calendar hasWeeks animate static" tabindex="-1" style="width: 1px;"><div class="flatpickr-months"><span class="flatpickr-prev-month"><svg version="1.1"
4. Other date fields seem to work correctly.
5. Docker setup: No additional proxy settings in DSM.
6. use.local.js.libs' => true

To 3. I don't know which information (code) from the inspector tab I should exactly provide.
If you need more information here, please point me to the right direction. I see "hidden" values for flatpickr-calendar element. When I set some values to "visible" it looks like: