CBUS/DALI possible interference issue

Hi All, as a newbie here, not sure if this is the right platform to ask, but will give it a try
I have a system with a 5500SHAC, Wiser C-Bus and DALI gateway, driving two separate DALI circuits (! upstairs lights, 1 downstairs lights).

The guy I bought the house from had a bunch of cowboy installers - system was not programmed correctly, have figured out which lights were at what DALI addresses, which keypads etc and matched everything up so I have a functioning system.

Problem I have is in the mornings and evenings ONE of the LED downlights on the downstairs DALI (it is in a group of 4 - called Dining Room) flashes on and off for about 30 seconds then stops, and around the same time 2 lights upstaris flash - one in the bathroom (which is on the Upstairs DALI, group of 6 lights but only one flashes) and another one in the Rumpus room (Upstairs DALI, Rumpus is a group of 4 also but again only one out of the 4 flashes).
I think it may be due to mains interference via Off Peak Hot Water Service signal that the energy authority injects down the lines at various times, but it is strange that only one light in each group flashes. I have checked the LED drivers (Tridonic units), they are all configured correctly and identical.

Any ideas on how to fix this ?

 

is the blinking steady or just a litlle impulsive? - on the dali side set power recovery level to like 30% instead of default 100% and bus revovery to 30% as well.this will help you determine if the issue is on the Dali Bus side (faulty power supply maybe?) if the light only comes on at these flash intervals at 30% you coulld rule out Cbus issue and look at the dali network. if it is going to 100% light an issued call from Cbus then run network diagnostic on the cbus side and check logs, alternatively run a dali diagnostic do the same on Dali line. out of curiosity what dali gateway are you using.

 

I'm at Seven Hills. They come on at about 50% then quickly to 100%, then 50% and up to 100% again, does this for about 30 seconds then stops. Have set the power recovery level to 0% (on both CBUAS and each DALI ballast), replaced the DALI power supplies also. What I forgot to advise also is the one out of the group of 4 that comes on downstairs is on a dimmer channel which drives the DALI ballasts, and the ones upstairs are on relay channels, so they obviously come on at 100% when they flash, where as the downstairs one "ramps up" very quickly then back to zero. I have a video of this - https://youtube.com/shorts/uhp868P8eOI?si=LGK17C1c0wj_qG-P.
The DALI gateway is a Clipsal 5502DAL2PS.

 

Oh and correct re certain times of the day - around 6.00 - 7.00am, then in the evenings around 5.30pm, then again at 9.00 - 9.45pm then sometimes around 12.30am - 1.30am