We have 2 SG3452X switches connected with generic DAC SFP+ cable (waiting for TP-Link TL-SM5220-1M).

One of the switches has also a generic SFP BiDI SM/SC module connected to a Netgear Switch at the other end and one TL-SM5310-T module connected to a Synology NAS (E10G30-T2).

Problem - Any firmware update to 1.20.4/5/9/10 causes the populated SFP+ ports to start flapping about every 10 minutes (down and up), less often the one with TL-SM5310-T.

No such problem with 1.20.2. We will replace the DAC with the TP-link model. We can always move  the FO link to a media converter.

Or we can stay with the current firmware.