Yes, the Lexar Professional 2000x 256GB SD is compatible with the Sony Alpha A7R V.
Lexar Professional 2000x 256GB SD is V90 class. Clears: XAVC HS 4K (200 Mbps, requires U3); XAVC S 4K (200 Mbps, requires U3); XAVC S HD (100 Mbps, requires U3); XAVC HS 8K (400 Mbps, requires V60); XAVC S-I 4K (600 Mbps, requires V90); XAVC S-I HD (222 Mbps, requires V90).
“This camera supports CFexpress Type A memory cards and SD memory cards (UHS-I, UHS-II compatible).”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)