I got a three pack from BaeBae Goods on amazon for $19.99. They fit well and I appreciate having multiple because it’s no big deal to strip the bed down in the middle of the night— I never have to worry about trying to do a load of laundry before nap time.

This is the exact set I got but they do have other colors/patterns: https://www.amazon.com/Bassinet-Mattress-Collection-BaeBae-Goods/dp/B07445RTB7/ref=mp_s_a_1_3?dchild=1&keywords=BaeBae+Goods+Bassinet+Bed+Sheets+–+Bassinet+Fitted+Sheets+3+Pack+–+100%25+Jersey+Knit+Cotton+Cradle+Sheets+–+Bassinet+Bedding+for+Standard+Size+Oval+or+Rectangular+Bassinet+Pads+–+Bassinet+Sheet+for+Boy+%26+Girl&qid=1588727006&sr=8-3

Sorry for the big link— I’m on mobile.

Interesting. I got these, which may be the same as yours but different pattern. They still work for us though, so maybe not https://www.amazon.com/dp/B07445RTB7/ref=cm_sw_r_cp_apa_i_cfmGCbN9B766Z