php: obtenga un formato de fecha modificado específico de los pedidos de WooCommerce

Estoy usando get_the_modified_date() función para obtener la última fecha en que se actualizó un pedido, estoy tratando de enviar el formato de esta manera:

get_the_modified_date( "F j, Y, g:i a", $order );

Pero obtengo una cadena vacía, si elimino el argumento de formato:

get_the_modified_date( $order );

Obtengo el siguiente resultado:

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00:27:41.000000","312401-05:001220201-05:00_3120p-05:00":1,"312401-05:001220201-05:00":"+00:00"},"1324202020-01-13T11:24:20-05:002020000000131_31202031amlunes":"0","1324202020-01-13T11:24:20-05:002020000000131_31amx":"0","201124pp24111_31202031amlunes":"16000","201124pp24111_31amx":"0","2020-01-13T11:24:20-05:00amLun, 13 Ene 2020 11:24:20 -050031_31amx":"0","31202031amlunes":"111000","31202031amlunes_31amx":"0","2020-01-13T11:24:20-05:000000002031202001-05:00Lun, 13 Ene 2020 11:24:20 -0500_2413":601,"2020Lun, 13 Ene 2020 11:24:20 -050013-05:00Lun, 13 Ene 2020 11:24:20 -0500_k-05:0020":"12020-01-13T11:24:20-05:00_2020Lun, 13 Ene 2020 11:24:20 -050013-05:00Lun, 13 Ene 2020 11:24:20 -0500_113VthAM-05:00Lun, 13 Ene 2020 11:24:20 -0500072510002020-01-13T11:24:20-05:001","b24luneslunes24111":{"f24Lun, 13 Ene 2020 11:24:20 -05002031_1am01-05:00":"amLun, 13 Ene 2020 11:24:20 -05002020-01-13T11:24:20-05:0011am111-05:00lunes 20-05:002020-01-13T11:24:20-05:00Lun, 13 Ene 2020 11:24:20 -0500-05:003120","lunesam2031_1am01-05:00":"","2020-01-13T11:24:20-05:00202001pam120":"","am1313Lun, 13 Ene 2020 11:24:20 -0500-05:002020_1":"2020-01-13T11:24:20-05:00Lun, 13 Ene 2020 11:24:20 -0500am 16 12020 26-24","am1313Lun, 13 Ene 2020 11:24:20 -0500-05:002020_2":"","2020-01-13T11:24:20-05:00243120":"AMLun, 13 Ene 2020 11:24:20 -050001-05:00124am","2031am31-05:00":"Q15789326600","p202020312020-01-13T11:24:20-05:00202013-05:00":"","2020-01-13T11:24:20-05:002020000000131Lun, 13 Ene 2020 11:24:20 -050020":"C-0500","-05:0001am24lunes":"am1301241@amLun, 13 Ene 2020 11:24:20 -05002020-01-13T11:24:20-05:0011am111-05:00lunes20-05:002020-01-13T11:24:20-05:00Lun, 13 Ene 2020 11:24:20 -0500-05:003120.2020-01-13T11:24:20-05:00202001","p1120201-05:00":"3206280962"},"201124pp24111":{"f24Lun, 13 Ene 2020 11:24:20 -05002031_1am01-05:00":"amLun, 13 Ene 2020 11:24:20 -05002020-01-13T11:24:20-05:0011am111-05:00lunes 20-05:002020-01-13T11:24:20-05:00Lun, 13 Ene 2020 11:24:20 -0500-05:003120","lunesam2031_1am01-05:00":"","2020-01-13T11:24:20-05:00202001pam120":"","am1313Lun, 13 Ene 2020 11:24:20 -0500-05:002020_1":"2020-01-13T11:24:20-05:00Lun, 13 Ene 2020 11:24:20 -0500am 16 12020 26-24","am1313Lun, 13 Ene 2020 11:24:20 -0500-05:002020_2":"","2020-01-13T11:24:20-05:00243120":"AMLun, 13 Ene 2020 11:24:20 -050001-05:00124am","2031am31-05:00":"Q15789326600","p202020312020-01-13T11:24:20-05:00202013-05:00":"","2020-01-13T11:24:20-05:002020000000131Lun, 13 Ene 2020 11:24:20 -050020":"C-0500"},"pam2001-05:00131_01-05:003111202013":"120202020-01-05:00Lun, 13 Ene 2020 11:24:20 -05002020-01-13T11:24:20-05:00am132020-pam112020-bam20242020-01-13T11:24:20-05:00","pam2001-05:00131_01-05:003111202013_312431lunes-05:00":"-05:00am11am p2020Lun, 13 Ene 2020 11:24:20 -0500 Ef-05:002020-01-13T11:24:20-05:003120, GMT-0500amLun, 13 Ene 2020 11:24:20 -050013-05:0031am 13-05:00 2020-01-13T11:24:20-05:00Lun, 13 Ene 2020 11:24:20 -0500u00-05:0091324312020, -05:00thE, -05:00312020-01-13T11:24:20-05:00","31Lun, 13 Ene 2020 11:24:20 -0500am120am2020-01-13T11:24:20-05:00312420201_2413":"","2020-01-13T11:24:20-05:000000002031202001-05:00Lun, 13 Ene 2020 11:24:20 -0500_24p_am1313Lun, 13 Ene 2020 11:24:20 -0500-05:002020":"181.51.186.231","2020-01-13T11:24:20-05:000000002031202001-05:00Lun, 13 Ene 2020 11:24:20 -0500_00000020-05:00Lun, 13 Ene 2020 11:24:20 -0500_am11-05:00131":"Ene20201224luneslunesam/5.0 (Eneam2020-01-13T11:24:20-05:002413120202011; 0131-05:00lunes Eneam2020-01-13T11:24:20-05:00 -0500th X 10_14_6) AMpplunes-05:0003-05:00bK2431/537.36 (K11GMT-0500Ene1, lunes24k-05:00 11-05:002020-01-13T11:24:20-05:00k2020) C11Lun, 13 Ene 2020 11:24:20 -0500202001-05:00/86.0.4240.198 thamfamLun, 13 Ene 2020 11:24:20 -050024/537.36","2020-01-13T11:24:20-05:00Lun, 13 Ene 2020 11:24:20 -0500-05:00am31-05:0013_00024am":"2020-01-13T11:24:20-05:0011-05:002020-01-13T11:24:20-05:00k202000000031","2020-01-13T11:24:20-05:000000002031202001-05:00Lun, 13 Ene 2020 11:24:20 -0500_1202031-05:00":"","13am31-05:00_2020-01-13T11:24:20-05:00202001plunes-05:0031-05:0013":{"13am31-05:00":"2020-11-26 19:58:19.000000","312401-05:001220201-05:00_3120p-05:00":1,"312401-05:001220201-05:00":"+00:00"},"13am31-05:00_pam2413":{"13am31-05:00":"2020-11-26 19:58:19.000000","312401-05:001220201-05:00_3120p-05:00":1,"312401-05:001220201-05:00":"+00:00"},"2020-01-13T11:24:20-05:00amLun, 13 Ene 2020 11:24:20 -050031_11am2011":"-05:002b692375182020-01-13T11:24:20-05:00b13265f62020-01-13T11:24:20-05:00742f13132649am1","100000001b-05:00Lun, 13 Ene 2020 11:24:20 -0500":"64365","01-05:0031am_13am31am":[{"2413":1133460,"k-05:0020":"01am24lunes2020-01-13T11:24:20-05:00112401p_1202020202020-01-13T11:24:20-05:0020200101-05:00Lun, 13 Ene 2020 11:24:20 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¿Podría decirme por qué el formato de fecha no funciona con esta función?