Is it possible to selectively NOT assign an IPv6 address on a router?

Question

Yandex

I ran into a problem with some Yandex.Station functions not working correctly. Namely:

Some radios stop working if IPv6 is available on the network. Moreover, the IPv4 region does not correspond to the IPv6 region.

For example:
IPv4 -- 109.203.19*.** -- Barnaul (home region) IPv6 -- 2a0d
:8340:90e:5555:44a2:af0:*:* (Station address) -- Moscow

then everything starts working as it should.
It is impossible to forcefully disable IPv6 on the station itself, because there are no controls available.
I opened a ticket in Yandex support, but for the third month they have been silent.
Maybe there is some way to make it so that the Station's router is not forced to assign an IPv6 address?
Or is there some other way to solve the problem?

On the router firmware from Padavan'a