This bug still exists in kernel 5.9.8:

[67065.670557] wlan0: deauthenticating from e4:aa:5d:e0:e5:60 by local choice (Reason: 3=DEAUTH_LEAVING)
[67065.684606] iwlwifi 0000:02:00.0: RF_KILL bit toggled to disable radio.
[67065.684608] iwlwifi 0000:02:00.0: reporting RF_KILL (radio disabled)
[67065.684620] iwlwifi 0000:02:00.0: HCMD_ACTIVE already clear for command MAC_PM_POWER_TABLE
[67065.698120] ------------[ cut here ]------------
[67065.698122] UMAC scan UID 0 status was not cleaned
[67065.698160] WARNING: CPU: 3 PID: 43706 at drivers/net/wireless/intel/iwlwifi/mvm/mac80211.c:1246 __iwl_mvm_mac_stop+0x14f/0x160 [iwlmvm]
[67065.698161] Modules linked in: ccm md4 cmac nls_utf8 fscache libdes snd_usb_audio snd_usbmidi_lib snd_seq_dummy snd_hrtimer xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 bridge stp llc bnep overlay binfmt_misc snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_soc_skl snd_soc_sst_ipc dell_rbtn snd_soc_sst_dsp snd_hda_ext_core snd_soc_acpi_intel_match snd_soc_acpi snd_soc_core mei_hdcp nls_iso8859_1 intel_rapl_msr snd_compress ac97_bus dell_laptop ledtrig_audio x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel snd_pcm_dmaengine dell_smm_hwmon i915 snd_hda_intel kvm snd_intel_dspcfg snd_hda_codec snd_hda_core snd_hwdep crct10dif_pclmul ghash_clmulni_intel snd_pcm snd_seq_midi snd_seq_midi_event joydev snd_rawmidi aesni_intel crypto_simd cryptd glue_helper drm_kms_helper snd_seq iwlmvm uvcvideo rapl videobuf2_vmalloc mac80211 videobuf2_memops
[67065.698181]  videobuf2_v4l2 intel_wmi_thunderbolt intel_cstate libarc4 btusb snd_seq_device btrtl dell_wmi snd_timer btbcm dell_smbios dcdbas efi_pstore btintel input_leds wmi_bmof serio_raw dell_wmi_descriptor iwlwifi bluetooth mousedev cec videobuf2_common rc_core i2c_algo_bit videodev ecdh_generic fb_sys_fops ecc snd syscopyarea ee1004 sysfillrect mc hid_multitouch sysimgblt cfg80211 intel_pch_thermal soundcore mei_me mei processor_thermal_device intel_rapl_common intel_soc_dts_iosf intel_xhci_usb_role_switch roles ucsi_acpi typec_ucsi typec int3400_thermal dell_smo8800 acpi_thermal_rel int3403_thermal intel_hid int340x_thermal_zone sparse_keymap acpi_pad mac_hid nf_tables sch_fq_codel nfnetlink parport_pc ppdev lp parport drm ip_tables x_tables autofs4 usbhid btrfs blake2b_generic xor raid6_pq libcrc32c hid_generic i2c_designware_platform rtsx_pci_sdmmc i2c_designware_core nvme crc32_pclmul e1000e i2c_i801 i2c_smbus rtsx_pci nvme_core ahci libahci intel_lpss_pci intel_lpss idma64
[67065.698209]  xhci_pci virt_dma xhci_pci_renesas wmi i2c_hid hid video backlight [last unloaded: cifs]
[67065.698214] CPU: 3 PID: 43706 Comm: NetworkManager Not tainted 5.9.8-050908-generic #202011101634
[67065.698215] Hardware name: Dell Inc. Latitude 5590/0VYDFF, BIOS 1.14.0 07/15/2020
[67065.698223] RIP: 0010:__iwl_mvm_mac_stop+0x14f/0x160 [iwlmvm]
[67065.698224] Code: aa 04 00 00 74 0e 42 c7 84 a3 fc 17 00 00 00 00 00 00 eb be 44 89 e6 48 c7 c7 90 7a e3 c0 c6 05 77 aa 04 00 01 e8 54 86 b7 c3 <0f> 0b eb d8 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1f 44 00 00
[67065.698225] RSP: 0018:ffffc282018cbc48 EFLAGS: 00010286
[67065.698227] RAX: 0000000000000000 RBX: ffffa0048f0f1ec8 RCX: ffffa004ae598cc8
[67065.698227] RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffffa004ae598cc0
[67065.698228] RBP: ffffc282018cbc60 R08: 0000000000000004 R09: 0000000000000533
[67065.698229] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
[67065.698229] R13: ffffa0048f0f2d48 R14: ffffa0048f0f1ec8 R15: ffffa0048f0f0ff0
[67065.698231] FS:  00007fe5b0430bc0(0000) GS:ffffa004ae580000(0000) knlGS:0000000000000000
[67065.698232] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[67065.698232] CR2: 000055ab7e76f230 CR3: 0000000417fec005 CR4: 00000000003706e0
[67065.698233] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[67065.698234] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[67065.698235] Call Trace:
[67065.698244]  iwl_mvm_mac_stop+0x6a/0x90 [iwlmvm]
[67065.698264]  drv_stop+0x39/0x110 [mac80211]
[67065.698283]  ieee80211_stop_device+0x46/0x50 [mac80211]
[67065.698300]  ieee80211_do_stop+0x551/0x860 [mac80211]
[67065.698303]  ? _raw_spin_unlock_bh+0x1e/0x20
[67065.698319]  ieee80211_stop+0x1a/0x20 [mac80211]
[67065.698322]  __dev_close_many+0xa2/0x110
[67065.698324]  dev_close_many+0x85/0x130
[67065.698325]  dev_close+0x5e/0x80
[67065.698343]  cfg80211_shutdown_all_interfaces+0x77/0xd0 [cfg80211]
[67065.698355]  cfg80211_rfkill_set_block+0x26/0x40 [cfg80211]
[67065.698357]  rfkill_set_block+0x9b/0x170
[67065.698359]  rfkill_fop_write+0x136/0x1e0
[67065.698361]  vfs_write+0xcd/0x210
[67065.698363]  ksys_write+0xb1/0xe0
[67065.698365]  ? exit_to_user_mode_prepare+0x3b/0xd0
[67065.698367]  __x64_sys_write+0x1a/0x20
[67065.698369]  do_syscall_64+0x38/0x90
[67065.698370]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[67065.698372] RIP: 0033:0x7fe5b19a6aaf
[67065.698374] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 b9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 0c fd ff ff 48
[67065.698375] RSP: 002b:00007ffd7e2b1940 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[67065.698376] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe5b19a6aaf
[67065.698377] RDX: 0000000000000008 RSI: 00007ffd7e2b1978 RDI: 000000000000001c
[67065.698378] RBP: 000000000000001c R08: 0000000000000000 R09: 0000000000000001
[67065.698378] R10: 0000000000000000 R11: 0000000000000293 R12: 0000559e0da07010
[67065.698379] R13: 0000000000000000 R14: 0000559e0c5be4bd R15: 0000000000000006
[67065.698381] ---[ end trace 705b81fd8f39cd63 ]---