Letters in front panel display

[jukkal2]

I have had an Ultimo 4K with a VU+ FBC 8 x DVB-C tuner since October, and it works fine.
I'm just wondering a strange thing in the front panel display.
At first, when I switched the receiver to standby, it showed a little "A" briefly in the lower left corner of the front display, then the "A" disappeared unless there was some recording going on. Sometimes there are more letters if multiple recordings are going on. I suppose this means which tuner units are on.
But lately, I think it has been since I updated to image 5.4.003, the "A" doesn't always go off, it often stays on even when there are no recordings going on and no timers about to start in the near future. And there may be A and B showing if there is just one recording going on.
Not a big deal, but I'm just curious. Does this mean that 5.4.003 leaves a tuner on in standby, unlike the previous images I have had in the receiver (5.2.004, 5.2.045, 5.4.001 and 5.4.002)? Or is there something not very obvious wrong in the hardware?
In case it matters, my front panel theme is set to default, and in the panel settings I have REC symbol on and REC symbol in standby on, but I haven't seen any other REC symbols in the panel but the letters in the lower left corner.

[ccs]

No tuner letters show on mine unless it is recording.

Any streaming going on from the box, deliberate or otherwise?

[jukkal2]

No tuner letters show on mine unless it is recording.

Any streaming going on from the box, deliberate or otherwise?

No streaming going on in those cases. Nobody using WebIf, and the router doesn't direct any outside network traffic to the receiver.
(Before coming to see the possible replies now I just turned it to standby after watching the news broadcast, it showed "AB" for a moment, then the A disappeared leaving only B. But there is Schitt's Creek being recorded, so the tuner is expected to stay on. So it doesn't always happen.)

[cactikid]

Might i ask if other boxes are are using those tuners as i left a box on downstairs and a letter shows up saying that tuner is in use.Box downstairs does not have a working sat feed

[v8rick]

Might i ask if other boxes are are using those tuners as i left a box on downstairs and a letter shows up saying that tuner is in use.Box downstairs does not have a working sat feed

yes that happens to me, Zero behind TV can't see light

[jukkal2]

Might i ask if other boxes are are using those tuners as i left a box on downstairs and a letter shows up saying that tuner is in use.Box downstairs does not have a working sat feed

There are no other boxes connected to it.

[Orlandox]

Can it be EPG Refresh going on ?

[jukkal2]

Can it be EPG Refresh going on ?

Could be, if it does that in offline state. I had an Ultimo, and occasionally I noticed that the EPG in some rarely watched tv channels seemed to only update when I turned the receiver to that channel for a while. If the current image does EPG refreshing on background when offline, that might explain a tuner being occasionally on with no apparent reason.