Hap AX S sfp flapping

RouterOS Beginner Basics
1

Hi everyone,
sorry if this is a newbie question, I’m still learning MikroTik

I’m using a hAP ax S as a fiber optic endpoint, connected via SC 1.25G SFP to a CRS112.
On the same CRS112 I have another fiber link using the same SFP modules, and that link works perfectly.

The link between hAP ax S and CRS112 comes up correctly and stays stable at idle or with low traffic.
However, when I put some load on it (higher throughput) the connection becomes unstable: packet loss, link flapping, and sometimes the link crashes completely. After a reboot it usually comes back, but the problem reappears as soon as traffic increases again.

I also checked the optical levels, and the TX/RX dBm values look normal and within expected ranges on both sides.

I also already tried changing auto-negotiation settings (on and off), without any improvement.

I tried to replace the sfp module without any improvement.

Since the same SFP modules work fine on another CRS port, I suspect this might be something specific to the hAP ax S, possibly related to power or thermal limits on the SFP cage.

Has anyone seen similar behavior with hAP ax S?
Are there known good SC 1.25G SFP modules for this device?

Thanks a lot for any help, and sorry again if I’m missing something obvious.

2

Since this is a relatively new device (there are not a lot having experience with it) it might be wise to create a support ticket and include supout.rif file (ideally when the problem occurs).
That would allow support to investigate what's happening.

3

Hello,

I've seen this happen on a device that was running RouterOS on an older version and RouterBOOT.

Check in System -> RouterBoard if it's up to date.

If you're going to update, back up your settings first.