Edges cropped on all streaming video to certain TV

I have an older TV in the side room - a Sony rear-projection HDTV, but in 4:3 aspect ratio. Whenever I stream a video to it via Serviio, the left/right edges are cut off. This is highly annoying. This does NOT happen with any other TV in the house (all the rest are 16:9 aspect ratio). It isn't an encoding issue, as it happens with all videos, regardless of how they're encoded - MPEG-TS, MKV, x.264, it doesn't matter.

FYI: All streaming clients of Serviio in the house are Sony Blu-Ray players. Either BDP-S370 or BDP-S470. Using the correct Sony profile in Serviio 0.6.2.

I did go through the on-screen settings on both that TV and the Blu-Ray player, looking for a setting that may be wrong - I didn't find anything, but that means little (who understands all of that gibberish?).

The only thing that I can think of is the fact that Serviio outputs only 1080p video - I believe this TV is not listed as being able to receive 1080p - 1080i or 720p only. There are a LOT of TV's out there like this - anyone else run into this issue? Maybe it's something else?

[Illico]

What is the profile selected on Serviio console device list ?

Sony BD Player/SMP - as I stated, the version that comes with 0.6.2.

[Illico]

The only thing that I can think of is the fact that Serviio outputs only 1080p video - I believe this TV is not listed as being able to receive 1080p - 1080i or 720p only. There are a LOT of TV's out there like this - anyone else run into this issue? Maybe it's something else?

Serviio delivered the media file with the same source resolution to the DLNA device (Sony BDP), but then the Sony BDP delivered the video to the TV via HDMI and probably make an upsale depending of the BDP setting (you probably see a 1080p or 1080i text on top-left when TV and BDP are powered-on).
Could you check the BDP setting and change the hdmi output setting to 576 or auto resolution?

Assumption is incorrect. Blu-Ray is connected via Component, not HDMI. This is a pre-HDMI HDTV.

I will see if I can fiddle with Blu-Ray settings some more as you suggest and report back.

Tried switching output as suggested. No effect.

The BDP-S470 doesn't have an "auto resolution" setting. Best I can do is pick 1080i, 720p, 576i, 576p. 1080p is greyed out. I tested all available (to me) settings. No effect. Sides of video still cropped off.