Computer internet loss when TV box is connected

[news]

[wireless]

Hi,
I have 1 gig fiber and my network is as follows:
fiber modem thingy - router - unmanaged switch (D-Link) - PC and PS4 on the switch.
This setup works at full 1 gig speed.
I wanted to move TV to the same room so I connected my TV box to the same switch and now my PC and PS4 say no internet when TV box is connected to the switch.
TV works as expected; it also works as single device on the switch.
How do I fix it?
Thanks


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